java io进修（二十一） FileReader和FileWriter

FileReader和FileWriter源码阐明

1. FileReader 源码(基于jdk1.7.40)

package java.io;
     
public class FileReader extends InputStreamReader {
     
    public FileReader(String fileName) throws FileNotFoundException {
        super(new FileInputStream(fil java io系列21之 InputStreamReader和OutputStreamWritereName));
    }
     
    public FileReader(File file) throws FileNotFoundException {
        super(new FileInputStream(file));
    }
     
    public FileReader(FileDescriptor fd) {
        super(new FileInputStream(fd));
    }
}

从中，我们可以看出FileReader是基于InputStreamReader实现的。

2. FileWriter 源码(基于jdk1.7.40)

package java.io;
     
public class FileWriter extends OutputStreamWriter {
     
    public FileWriter(String fileName) throws IOException {
        super(new FileOutputStream(fileName));
    }
     
    public FileWriter(String fileName, boolean append) throws IOException {
        super(new FileOutputStream(fileName, append));
    }
     
    public FileWriter(File file) throws IOException {
        super(new FileOutputStream(file));
    }
     
    public FileWriter(File file, boolean append) throws IOException {
        super(new FileOutputStream(file, append));
    }
     
    public FileWriter(FileDescriptor fd) {
        super(new FileOutputStream(fd));
    }
}

从中，我们可以看出FileWriter是基于OutputStreamWriter实现的。

示例措施

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.FileWriter;;

import java.io.FileReader;

import java.io.IOException;
/**

 * FileReader 和 FileWriter 测试措施

 *

 * @author skywang

 */

public class FileReaderWriterTest {
    private static final String FileName = "file.txt";

    private static final String CharsetName = "utf-8";
    public static void main(String[] args) {

        testWrite();

        testRead();

    }
    /**

     * OutputStreamWriter 演示函数

     *

     */

    private static void testWrite() {

        try {

            // 建设文件“file.txt”对应File工具

            File file = new File(FileName);

            // 建设FileOutputStream对应FileWriter：将字节约转换为字符流，即写入out1的数据会自动由字节转换为字符。

			// 查察本栏目
c1=字
buf=流示例0123456
来历：http://www.cnblogs.com/skywang12345/p/io_22.html