java 将一个文本文件中的内容复制到零一个文本文件中，用到IO流

package com.ggx.exercise;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;

import org.junit.Test;

public class copyText {

	@Test
	public void test() {
		copyTextbyChar("e:\\in.txt", "e:\\out.txt");//调用方法（传递路径），灵活；
	}

	public void copyTextbyChar(String sourceName, String targetName) {

		FileReader reader = null;
		FileWriter writer = null;
		try {
			reader = new FileReader(sourceName);

			writer = new FileWriter(targetName);
			
			int len = -1;
			while ( (len = reader.read()) != -1 ){//若读到-1，则说明文件读到了末尾；
				writer.write(len);  //逐个读取字符，然后逐个写入进targetName文件中；
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {

			try {
				if (reader != null)
					reader.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			try {
				if (writer != null)
					writer.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}