学步园

package com.tom;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;

public class TestF {
	public static void main(String[] args) throws IOException {
		//"." :当前project的路径
		File file0 = new File("./1.txt");
		System.out.println(file0.exists());
		File file01 = new File("1.txt");
		System.out.println(file01.exists());
		String filePath = "./"+"bulk"+"/"+"abc.xls";
		File file = new File(filePath);
		file.getParentFile().mkdirs();
		try {
			file.createNewFile();
			System.out.println("successfully create files!");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		File file2 = new File("abc/2.txt");
		System.out.println(file2.exists());
		File file21 = new File("./abc/2.txt");
		System.out.println(file21.exists());
		File file3 = new File("./src/3.txt");
		System.out.println(file3.exists());
		//src目录下的文件会被编译到bin目录
		File file4 = new File("./bin/3.txt");
		System.out.println(file4.exists());
		File file5 = new File("bin/3.txt");
		System.out.println(file5.exists());
		//但是bin是classpath,所以可以这么读取
		//"/"代表classpath,绝对路径
		String f = TestF.class.getResource("/4.txt").getPath();
		System.out.println(f);
		//不以"/"开头，则认为是从当前类所在路径上3层开始读取
		String f1 = TestF.class.getResource("../../4.txt").getPath();
		System.out.println(f1);
		//和当前类在同一个包里，用绝对路径读取
		String f2 = TestF.class.getResource("/com/tom/5.txt").getPath();
		System.out.println(f2);
		//用相对路径读取
		String f21 = TestF.class.getResource("5.txt").getPath();
		System.out.println(f21);
		//读取子包下面的7.txt
		String f22 = TestF.class.getResource("/com/tom/jimi/7.txt").getPath();
		System.out.println(f22);
		String f23 = TestF.class.getResource("jimi/7.txt").getPath();
		System.out.println(f23);
		
		String f3 = TestF.class.getClassLoader().getResource("com/tom/6.txt").getPath(); 
		System.out.println(f3);
		String f4 = TestF.class.getClassLoader().getResource("4.txt").getPath(); 
		System.out.println(f4);
		
		File file7 = new File("./bin/com/tom/jimi/7.txt");
		System.out.println(file7.exists());
		File file8 = new File("./src/com/tom/jimi/7.txt");
		System.out.println(file8.exists());
		System.out.println(readFile("5.txt"));
		System.out.println(readFile("jimi/7.txt"));
		System.out.println(readFile("/com/kao/8.txt"));
	}
	public static String readFile(String fileName) throws IOException {
	    BufferedReader br = new BufferedReader(new InputStreamReader(TestF.class.getResourceAsStream(fileName)));
	    try {
	        StringBuilder sb = new StringBuilder();
	        String line = br.readLine();

	        while (line != null) {
	            sb.append(line);
	            sb.append("\n");
	            line = br.readLine();
	        }
	        return sb.toString();
	    } finally {
	        br.close();
	    }
	}
}

</pre><pre name="code" class="java"><img src="http://img.blog.csdn.net/20141125233533765" alt="" />