java文件字符编码检测和转换

package com.product.codetools.encoding; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.FilenameFilter; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.nio.charset.Charset; import java.nio.charset.UnsupportedCharsetException; public class FileCharsetConverter { public static void main(String[] args) throws Exception { FileCharsetConverter.convert( "gbk/DispatcherHandler.java", "GBK", "UTF-8", new FilenameFilter() { public boolean accept(File dir, String name) { return name.endsWith(".java"); } }); } /** * 把指定文件或目录转换成指定的编码 * * @param fileName * 要转换的文件 * @param fromCharsetName * 源文件的编码 * @param toCharsetName * 要转换的编码 * @throws Exception */ public static void convert(String fileName, String fromCharsetName, String toCharsetName) throws Exception { convert(new File(fileName), fromCharsetName, toCharsetName, null); } /** * 把指定文件或目录转换成指定的编码 * * @param file * 要转换的文件或目录 * @param fromCharsetName * 源文件的编码 * @param toCharsetName * 要转换的编码 * @throws Exception */ public static void convert(File file, String fromCharsetName, String toCharsetName) throws Exception { convert(file, fromCharsetName, toCharsetName, null); } /** * 把指定文件或目录转换成指定的编码 * * @param file * 要转换的文件或目录 * @param fromCharsetName * 源文件的编码 * @param toCharsetName * 要转换的编码 * @param filter * 文件名过滤器 * @throws Exception */ public static void convert(String fileName, String fromCharsetName, String toCharsetName, FilenameFilter filter) throws Exception { convert(new File(fileName), fromCharsetName, toCharsetName, filter); } /** * 把指定文件或目录转换成指定的编码 * * @param file * 要转换的文件或目录 * @param fromCharsetName * 源文件的编码 * @param toCharsetName * 要转换的编码 * @param filter * 文件名过滤器 * @throws Exception */ public static void convert(File file, String fromCharsetName, String toCharsetName, FilenameFilter filter) throws Exception { if (file.isDirectory()) { File[] fileList = null; if (filter == null) { fileList = file.listFiles(); } else { fileList = file.listFiles(filter); } for (File f : fileList) { convert(f, fromCharsetName, toCharsetName, filter); } } else { if (filter == null || filter.accept(file.getParentFile(), file.getName())) { String fileContent = getFileContentFromCharset(file, fromCharsetName); saveFile2Charset(file, toCharsetName, fileContent); } } } /** * 以指定编码方式读取文件，返回文件内容 * * @param file * 要转换的文件 * @param fromCharsetName * 源文件的编码 * @return * @throws Exception */ public static String getFileContentFromCharset(File file, String fromCharsetName) throws Exception { if (!Charset.isSupported(fromCharsetName)) { throw new UnsupportedCharsetException(fromCharsetName); } InputStream inputStream = new FileInputStream(file); InputStreamReader reader = new InputStreamReader(inputStream, fromCharsetName); char[] chs = new char[(int) file.length()]; reader.read(chs); String str = new String(chs).trim(); reader.close(); return str; } /** * 以指定编码方式写文本文件，存在会覆盖 * * @param file * 要写入的文件 * @param toCharsetName * 要转换的编码 * @param content * 文件内容 * @throws Exception */ public static void saveFile2Charset(File file, String toCharsetName, String content) throws Exception { if (!Charset.isSupported(toCharsetName)) { throw new UnsupportedCharsetException(toCharsetName); } OutputStream outputStream = new FileOutputStream(file); OutputStreamWriter outWrite = new OutputStreamWriter(outputStream, toCharsetName); outWrite.write(content); outWrite.close(); } }