java文件写入

以你之姓@ 2022-06-08 00:29 170阅读 0赞

package com.anran.filereader;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.io.RandomAccessFile;
    import java.nio.ByteBuffer;
    import java.nio.channels.FileChannel;
    
    /** * @author anran * @version 创建时间：2017年9月9日 上午9:09:44 类说明 : */
    public class WriteFile { 
    
        public static void main(String[] args) throws IOException {
            String path = "C:\\Users\\Administrator\\Desktop\\ecplise快捷键.txt";
            String targetPath = "C:\\Users\\Administrator\\Desktop\\text.txt";
            // fileWriteByInputStream(path, targetPath);
            // fileWriteByFileInputStream(path, targetPath);
            // fileWriteByBufferedReader(path, targetPath);
            // fileWriteByBufferedWriter(targetPath, "AAA安然AAA");
            // fileWriteByFileWriter(targetPath, "CCCC安然CCCCC");
            fileWriteByRandomAccessFile(targetPath, "EEEE安然EEEEE");
        }
    
        // 会覆盖原有内容（相当于文件copy）
        public static void fileWriteByInputStream(String source, String target)
                throws IOException {
            try (InputStream in = new FileInputStream(source)) {
                try (OutputStream out = new FileOutputStream(target)) {
                    byte[] buffer = new byte[4096];
                    int bytesToRead;
                    while ((bytesToRead = in.read(buffer)) != -1) {
                        out.write(buffer, 0, bytesToRead);
                    }
                }
            }
        }
    
        // 会覆盖原有内容（相当于文件copy）
        public static void fileWriteByFileInputStream(String source, String target)
                throws IOException {
            try (FileInputStream in = new FileInputStream(source)) {
                try (FileOutputStream out = new FileOutputStream(target)) {
                    FileChannel inChannel = in.getChannel();
                    FileChannel outChannel = out.getChannel();
                    ByteBuffer buffer = ByteBuffer.allocate(4096);
                    while (inChannel.read(buffer) != -1) {
                        buffer.flip();
                        outChannel.write(buffer);
                        buffer.clear();
                    }
                }
            }
        }
    
        // 会覆盖原有内容（相当于文件copy）
        public static void fileWriteByBufferedReader(String source, String target)
                throws IOException {
            try (BufferedReader reader = new BufferedReader(new InputStreamReader(
                    new FileInputStream(source), "UTF-8"))) {
                try (BufferedWriter writer = new BufferedWriter(new FileWriter(
                        target))) {
                    String str = null;
                    while (null != (str = reader.readLine())) {
                        writer.write(str);
                        writer.write("\n");
                    }
                }
            }
        }
    
        // 文件中追加内容
        public static void fileWriteByBufferedWriter(String file, String conent)
                throws FileNotFoundException, IOException {
            // FileOutputStream构造器第二个参数设置为true是追加
            try (BufferedWriter out = new BufferedWriter(new OutputStreamWriter(
                    new FileOutputStream(file, true)))) {
                out.write(conent);
            }
        }
    
        // 文件中追加内容
        public static void fileWriteByFileWriter(String fileName, String content)
                throws IOException {
            // 打开一个写文件器，构造函数中的第二个参数true表示以追加形式写文件
            try (FileWriter writer = new FileWriter(fileName, true)) {
                writer.write(content);
            }
        }
    
        public static void fileWriteByRandomAccessFile(String fileName,
                String content) throws IOException {
            // 打开一个随机访问文件流，按读写方式
            try (RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw")) {
                // 文件长度，字节数
                long fileLength = randomFile.length();
                // 将写文件指针移到文件尾。
                randomFile.seek(fileLength);
                randomFile.write(content.getBytes());
            }
        }
    
    }