文件编码识别与编码格式转换 - java 源码

╰+攻爆jí腚メ 2021-12-22 12:59 344阅读 0赞

### 文章目录 ###

*   *  文件编码识别源码
     *  编码格式转换源码

## 文件编码识别源码 ##

*  转自：[java自动探测文件的字符编码][java]
 *  其中 chardet.jar 包可在 [主页下载][Link 1]，也可在 maven 仓库直接下载
 *  识别是通过统计数据得到的，可能不准

import org.mozilla.intl.chardet.nsDetector;
    import org.mozilla.intl.chardet.nsICharsetDetectionObserver;
    import java.io.BufferedInputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    
    
    public class FileCharsetDetector { 
        private boolean found = false;
        private String encoding = null;
    
        public static void main(String[] argv) throws Exception { 
            File file1 = new File("D:\\testg.txt");
    
            System.out.println("文件编码:" + new FileCharsetDetector().guessFileEncoding(file1));
        }
    
        /** * 传入一个文件(File)对象，检查文件编码 * * @param file * File对象实例 * @return 文件编码，若无，则返回null * @throws FileNotFoundException * @throws IOException */
        public String guessFileEncoding(File file) throws FileNotFoundException, IOException { 
            return guessFileEncoding(file, new nsDetector());
        }
    
        /** * <pre> * 获取文件的编码 * @param file * File对象实例 * @param languageHint * 语言提示区域代码 @see #nsPSMDetector ,取值如下： * 1 : Japanese * 2 : Chinese * 3 : Simplified Chinese * 4 : Traditional Chinese * 5 : Korean * 6 : Dont know(default) * </pre> * * @return 文件编码，eg：UTF-8,GBK,GB2312形式(不确定的时候，返回可能的字符编码序列)；若无，则返回null * @throws FileNotFoundException * @throws IOException */
        public String guessFileEncoding(File file, int languageHint) throws FileNotFoundException, IOException { 
            return guessFileEncoding(file, new nsDetector(languageHint));
        }
    
        /** * 获取文件的编码 * * @param file * @param det * @return * @throws FileNotFoundException * @throws IOException */
        private String guessFileEncoding(File file, nsDetector det) throws FileNotFoundException, IOException { 
            // Set an observer...
            // The Notify() will be called when a matching charset is found.
            det.Init(new nsICharsetDetectionObserver() { 
                public void Notify(String charset) { 
                    encoding = charset;
                    found = true;
                }
            });
    
            BufferedInputStream imp = new BufferedInputStream(new FileInputStream(file));
            byte[] buf = new byte[1024];
            int len;
            boolean done = false;
            boolean isAscii = false;
    
            while ((len = imp.read(buf, 0, buf.length)) != -1) { 
                // Check if the stream is only ascii.
                isAscii = det.isAscii(buf, len);
                if (isAscii) { 
                    break;
                }
                // DoIt if non-ascii and not done yet.
                done = det.DoIt(buf, len, false);
                if (done) { 
                    break;
                }
            }
            imp.close();
            det.DataEnd();
    
            if (isAscii) { 
                encoding = "ASCII";
                found = true;
            }
    
            if (!found) { 
                String[] prob = det.getProbableCharsets();
                //这里将可能的字符集组合起来返回
                for (int i = 0; i < prob.length; i++) { 
                    if (i == 0) { 
                        encoding = prob[i];
                    } else { 
                        encoding += "," + prob[i];
                    }
                }
    
                if (prob.length > 0) { 
                    // 在没有发现情况下,也可以只取第一个可能的编码,这里返回的是一个可能的序列
                    return encoding;
                } else { 
                    return null;
                }
            }
            return encoding;
        }
    }

## 编码格式转换源码 ##

*  递归找到目标路径下所有 .java 文件
 *  将这些文件格式转换为目标格式

public class ChangeEncoding { 
    
        public static void main(String[] args) throws IOException { 
            String path = "C:\\Users\\wangk\\Desktop\\多线程并发编程";
            String toEncoding = "utf-8";
            getAllJavaDoc(path,toEncoding);
        }
    
        private static void getAllJavaDoc(String path, String toEncoding) throws IOException { 
            File file = new File(path);
            File[] files = file.listFiles();
    
            for (File file1 : files) { 
                if(file1.isDirectory()) { 
                    getAllJavaDoc(path + "\\" + file1.getName(), toEncoding);
                } else { 
                    if(file1.getName().endsWith(".java")) { 
                        changeTo(file1,toEncoding);
                    }
                }
            }
        }
    
        private static void changeTo(File file1, String toEncoding) throws IOException { 
    
            String fromEncoding = new FileCharsetDetector().guessFileEncoding(file1);
            if(toEncoding.equalsIgnoreCase(fromEncoding)) return;
    
            BufferedReader bdf = new BufferedReader(new InputStreamReader(new FileInputStream(file1),fromEncoding));
    
            String str=null;
            StringBuilder context = new StringBuilder();
            while((str=bdf.readLine())!=null){ 
                context.append(str).append("\n");
            }
    
            BufferedWriter bdw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file1),toEncoding));
            bdw.write(context.toString());
            System.out.println("将" + file1.getPath() + "文件格式从 " + fromEncoding + " 转换为 " + toEncoding);
            bdw.close();
            bdf.close();
        }
    }

[java]: https://www.cnblogs.com/yejg1212/p/3402322.html
[Link 1]: http://jchardet.sourceforge.net/