Faster PrintWriter.
Change-Id: I4e1ae7e0357214deb7e19ae65f8701b69b347c6e
This commit is contained in:
Dianne Hackborn
@@ -17,6 +17,7 @@
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package android.os;
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import android.util.Log;
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import com.android.internal.util.FastPrintWriter;
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import java.io.FileDescriptor;
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import java.io.FileOutputStream;
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@@ -288,7 +289,7 @@ public class Binder implements IBinder {
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*/
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public void dump(FileDescriptor fd, String[] args) {
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FileOutputStream fout = new FileOutputStream(fd);
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PrintWriter pw = new PrintWriter(fout);
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PrintWriter pw = new FastPrintWriter(fout);
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try {
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final String disabled;
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synchronized (Binder.class) {
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@@ -310,7 +311,7 @@ public class Binder implements IBinder {
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*/
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public void dumpAsync(final FileDescriptor fd, final String[] args) {
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final FileOutputStream fout = new FileOutputStream(fd);
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final PrintWriter pw = new PrintWriter(fout);
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final PrintWriter pw = new FastPrintWriter(fout);
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Thread thr = new Thread("Binder.dumpAsync") {
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public void run() {
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try {
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478
core/java/com/android/internal/util/FastPrintWriter.java
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478
core/java/com/android/internal/util/FastPrintWriter.java
Normal file
@@ -0,0 +1,478 @@
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package com.android.internal.util;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.io.IOException;
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import java.io.OutputStream;
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import java.io.PrintWriter;
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import java.io.UnsupportedEncodingException;
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import java.io.Writer;
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import java.nio.ByteBuffer;
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import java.nio.CharBuffer;
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import java.nio.charset.Charset;
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import java.nio.charset.CharsetEncoder;
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import java.nio.charset.CoderResult;
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import java.nio.charset.CodingErrorAction;
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public class FastPrintWriter extends PrintWriter {
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private static final int BUFFER_LEN = 8192;
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private final char[] mText = new char[BUFFER_LEN];
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private int mPos;
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final private OutputStream mOutputStream;
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private CharsetEncoder mCharset;
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final private ByteBuffer mBytes = ByteBuffer.allocate(BUFFER_LEN);
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/**
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* Constructs a new {@code PrintWriter} with {@code out} as its target
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* stream. By default, the new print writer does not automatically flush its
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* contents to the target stream when a newline is encountered.
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*
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* @param out
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* the target output stream.
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* @throws NullPointerException
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* if {@code out} is {@code null}.
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*/
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public FastPrintWriter(OutputStream out) {
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super(out);
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mOutputStream = out;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with {@code out} as its target
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* stream. The parameter {@code autoFlush} determines if the print writer
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* automatically flushes its contents to the target stream when a newline is
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* encountered.
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*
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* @param out
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* the target output stream.
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* @param autoFlush
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* indicates whether contents are flushed upon encountering a
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* newline sequence.
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* @throws NullPointerException
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* if {@code out} is {@code null}.
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*/
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public FastPrintWriter(OutputStream out, boolean autoFlush) {
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super(out, autoFlush);
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mOutputStream = out;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with {@code wr} as its target
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* writer. By default, the new print writer does not automatically flush its
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* contents to the target writer when a newline is encountered.
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*
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* @param wr
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* the target writer.
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* @throws NullPointerException
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* if {@code wr} is {@code null}.
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*/
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public FastPrintWriter(Writer wr) {
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super(wr);
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mOutputStream = null;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with {@code out} as its target
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* writer. The parameter {@code autoFlush} determines if the print writer
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* automatically flushes its contents to the target writer when a newline is
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* encountered.
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*
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* @param wr
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* the target writer.
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* @param autoFlush
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* indicates whether to flush contents upon encountering a
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* newline sequence.
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* @throws NullPointerException
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* if {@code out} is {@code null}.
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*/
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public FastPrintWriter(Writer wr, boolean autoFlush) {
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super(wr, autoFlush);
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mOutputStream = null;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with {@code file} as its target. The
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* VM's default character set is used for character encoding.
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* The print writer does not automatically flush its contents to the target
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* file when a newline is encountered. The output to the file is buffered.
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*
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* @param file
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* the target file. If the file already exists, its contents are
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* removed, otherwise a new file is created.
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* @throws java.io.FileNotFoundException
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* if an error occurs while opening or creating the target file.
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*/
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public FastPrintWriter(File file) throws FileNotFoundException {
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super(file);
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mOutputStream = null;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with {@code file} as its target. The
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* character set named {@code csn} is used for character encoding.
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* The print writer does not automatically flush its contents to the target
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* file when a newline is encountered. The output to the file is buffered.
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*
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* @param file
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* the target file. If the file already exists, its contents are
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* removed, otherwise a new file is created.
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* @param csn
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* the name of the character set used for character encoding.
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* @throws FileNotFoundException
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* if an error occurs while opening or creating the target file.
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* @throws NullPointerException
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* if {@code csn} is {@code null}.
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* @throws java.io.UnsupportedEncodingException
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* if the encoding specified by {@code csn} is not supported.
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*/
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public FastPrintWriter(File file, String csn) throws FileNotFoundException,
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UnsupportedEncodingException {
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super(file, csn);
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mOutputStream = null;
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initEncoder(csn);
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}
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/**
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* Constructs a new {@code PrintWriter} with the file identified by {@code
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* fileName} as its target. The VM's default character set is
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* used for character encoding. The print writer does not automatically
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* flush its contents to the target file when a newline is encountered. The
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* output to the file is buffered.
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*
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* @param fileName
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* the target file's name. If the file already exists, its
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* contents are removed, otherwise a new file is created.
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* @throws FileNotFoundException
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* if an error occurs while opening or creating the target file.
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*/
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public FastPrintWriter(String fileName) throws FileNotFoundException {
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super(fileName);
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mOutputStream = null;
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initDefaultEncoder();
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}
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/**
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* Constructs a new {@code PrintWriter} with the file identified by {@code
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* fileName} as its target. The character set named {@code csn} is used for
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* character encoding. The print writer does not automatically flush its
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* contents to the target file when a newline is encountered. The output to
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* the file is buffered.
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*
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* @param fileName
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* the target file's name. If the file already exists, its
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* contents are removed, otherwise a new file is created.
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* @param csn
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* the name of the character set used for character encoding.
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* @throws FileNotFoundException
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* if an error occurs while opening or creating the target file.
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* @throws NullPointerException
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* if {@code csn} is {@code null}.
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* @throws UnsupportedEncodingException
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* if the encoding specified by {@code csn} is not supported.
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*/
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public FastPrintWriter(String fileName, String csn)
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throws FileNotFoundException, UnsupportedEncodingException {
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super(fileName, csn);
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mOutputStream = null;
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initEncoder(csn);
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}
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private final void initEncoder(String csn) throws UnsupportedEncodingException {
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try {
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mCharset = Charset.forName(csn).newEncoder();
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} catch (Exception e) {
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throw new UnsupportedEncodingException(csn);
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}
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mCharset.onMalformedInput(CodingErrorAction.REPLACE);
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mCharset.onUnmappableCharacter(CodingErrorAction.REPLACE);
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}
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private final void initDefaultEncoder() {
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mCharset = Charset.defaultCharset().newEncoder();
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mCharset.onMalformedInput(CodingErrorAction.REPLACE);
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mCharset.onUnmappableCharacter(CodingErrorAction.REPLACE);
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}
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private void appendInner(char c) throws IOException {
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int pos = mPos;
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if (pos >= (BUFFER_LEN-1)) {
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flush();
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pos = mPos;
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}
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mText[pos] = c;
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mPos = pos+1;
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}
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private void appendInner(String str, int i, final int length) throws IOException {
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if (length > BUFFER_LEN) {
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final int end = i + length;
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while (i < end) {
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int next = i + BUFFER_LEN;
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appendInner(str, i, next<end ? BUFFER_LEN : (end-i));
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i = next;
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}
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return;
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}
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int pos = mPos;
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if ((pos+length) > BUFFER_LEN) {
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flush();
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pos = mPos;
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}
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str.getChars(i, i + length, mText, pos);
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mPos = pos + length;
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}
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private void appendInner(char[] buf, int i, final int length) throws IOException {
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if (length > BUFFER_LEN) {
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final int end = i + length;
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while (i < end) {
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int next = i + BUFFER_LEN;
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appendInner(buf, i, next < end ? BUFFER_LEN : (end - i));
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i = next;
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}
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return;
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}
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int pos = mPos;
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if ((pos+length) > BUFFER_LEN) {
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flush();
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pos = mPos;
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}
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System.arraycopy(buf, i, mText, pos, length);
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mPos = pos + length;
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}
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private void flushBytesInner() throws IOException {
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int position;
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if ((position = mBytes.position()) > 0) {
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mBytes.flip();
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mOutputStream.write(mBytes.array(), 0, position);
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mBytes.clear();
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}
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}
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private void flushInner() throws IOException {
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//Log.i("PackageManager", "flush mPos=" + mPos);
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if (mPos > 0) {
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if (mOutputStream != null) {
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CharBuffer charBuffer = CharBuffer.wrap(mText, 0, mPos);
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CoderResult result = mCharset.encode(charBuffer, mBytes, true);
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while (true) {
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if (result.isError()) {
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throw new IOException(result.toString());
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} else if (result.isOverflow()) {
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flushBytesInner();
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result = mCharset.encode(charBuffer, mBytes, true);
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continue;
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}
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break;
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}
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flushBytesInner();
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mOutputStream.flush();
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} else {
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out.write(mText, 0, mPos);
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out.flush();
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}
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mPos = 0;
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}
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}
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/**
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* Ensures that all pending data is sent out to the target. It also
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* flushes the target. If an I/O error occurs, this writer's error
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* state is set to {@code true}.
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*/
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@Override
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public void flush() {
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try {
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flushInner();
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} catch (IOException e) {
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}
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super.flush();
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}
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/**
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* Prints the string representation of the specified character array
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* to the target.
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*
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* @param charArray
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* the character array to print to the target.
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* @see #print(String)
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*/
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public void print(char[] charArray) {
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try {
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appendInner(charArray, 0, charArray.length);
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} catch (IOException e) {
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}
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}
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/**
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* Prints the string representation of the specified character to the
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* target.
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*
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* @param ch
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* the character to print to the target.
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* @see #print(String)
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*/
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public void print(char ch) {
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try {
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appendInner(ch);
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} catch (IOException e) {
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}
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}
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/**
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* Prints a string to the target. The string is converted to an array of
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* bytes using the encoding chosen during the construction of this writer.
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* The bytes are then written to the target with {@code write(int)}.
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* <p>
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* If an I/O error occurs, this writer's error flag is set to {@code true}.
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*
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* @param str
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* the string to print to the target.
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* @see #write(int)
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*/
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public void print(String str) {
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if (str == null) {
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str = String.valueOf((Object) null);
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}
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try {
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appendInner(str, 0, str.length());
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} catch (IOException e) {
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}
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}
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/**
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* Prints the string representation of the character array {@code chars} followed by a newline.
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* Flushes this writer if the autoFlush flag is set to {@code true}.
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*/
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public void println(char[] chars) {
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print(chars);
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println();
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}
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/**
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* Prints the string representation of the char {@code c} followed by a newline.
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* Flushes this writer if the autoFlush flag is set to {@code true}.
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*/
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public void println(char c) {
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print(c);
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println();
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}
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/**
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* Writes {@code count} characters from {@code buffer} starting at {@code
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* offset} to the target.
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* <p>
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* This writer's error flag is set to {@code true} if this writer is closed
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* or an I/O error occurs.
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*
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* @param buf
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* the buffer to write to the target.
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* @param offset
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* the index of the first character in {@code buffer} to write.
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* @param count
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* the number of characters in {@code buffer} to write.
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* @throws IndexOutOfBoundsException
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* if {@code offset < 0} or {@code count < 0}, or if {@code
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* offset + count} is greater than the length of {@code buf}.
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*/
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@Override
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public void write(char[] buf, int offset, int count) {
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try {
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appendInner(buf, offset, count);
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} catch (IOException e) {
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}
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}
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/**
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* Writes one character to the target. Only the two least significant bytes
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* of the integer {@code oneChar} are written.
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* <p>
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* This writer's error flag is set to {@code true} if this writer is closed
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* or an I/O error occurs.
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*
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* @param oneChar
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* the character to write to the target.
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*/
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@Override
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public void write(int oneChar) {
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try {
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appendInner((char) oneChar);
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} catch (IOException e) {
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}
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}
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/**
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* Writes the characters from the specified string to the target.
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*
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* @param str
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* the non-null string containing the characters to write.
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*/
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@Override
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public void write(String str) {
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try {
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appendInner(str, 0, str.length());
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} catch (IOException e) {
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}
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}
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/**
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* Writes {@code count} characters from {@code str} starting at {@code
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* offset} to the target.
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*
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* @param str
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* the non-null string containing the characters to write.
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* @param offset
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* the index of the first character in {@code str} to write.
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* @param count
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* the number of characters from {@code str} to write.
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* @throws IndexOutOfBoundsException
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* if {@code offset < 0} or {@code count < 0}, or if {@code
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* offset + count} is greater than the length of {@code str}.
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*/
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@Override
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public void write(String str, int offset, int count) {
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try {
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appendInner(str, offset, count);
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} catch (IOException e) {
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}
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}
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/**
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* Appends a subsequence of the character sequence {@code csq} to the
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* target. This method works the same way as {@code
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* PrintWriter.print(csq.subsequence(start, end).toString())}. If {@code
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* csq} is {@code null}, then the specified subsequence of the string "null"
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* will be written to the target.
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*
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* @param csq
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* the character sequence appended to the target.
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* @param start
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* the index of the first char in the character sequence appended
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* to the target.
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* @param end
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* the index of the character following the last character of the
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* subsequence appended to the target.
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* @return this writer.
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* @throws StringIndexOutOfBoundsException
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* if {@code start > end}, {@code start < 0}, {@code end < 0} or
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* either {@code start} or {@code end} are greater or equal than
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* the length of {@code csq}.
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*/
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@Override
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public PrintWriter append(CharSequence csq, int start, int end) {
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if (csq == null) {
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csq = "null";
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}
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String output = csq.subSequence(start, end).toString();
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write(output, 0, output.length());
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return this;
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}
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}
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Reference in New Issue
Block a user