字符文件操作——题4,5

题1：
读取a文件将读取每行内容并在每行内容前加上描述其为第一行，写入另一文件中并打印出来。

package zuoye3;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class zuoye34 {
	public static void main(String [] args) throws IOException{
		FileReader reader = new FileReader ("C:\eclipse-jee-neon-3-RC3-win32-x86_64\a.txt");
		FileWriter writer = new FileWriter ("C:\eclipse-jee-neon-3-RC3-win32-x86_64\b.txt");
		Scanner sc = new Scanner(reader);
		int i = 0;
		String s2 = "第";
		String s3 = "行";
		String s4 = null;
		while(sc.hasNext()){
			i = (int)i+1;
			String s = sc.nextLine();
			String s1 = s2+String.valueOf(i)+s3+s;
			for(int j = 0;j 
题2：
 一个文本文件中储存C++，Python,Java等字样，统计其每个出现的次数。将其写为（**）出现了（n）次的形式。储存在另一文件中，并打印出来。要求使用FileReader、FileWriter、HashMap。
 
package zuoye3;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

public class zuoye35 {
	public static void main(String []args) throws IOException   {
		FileReader reader = new FileReader("C:\eclipse-jee-neon-3-RC3-win32-x86_64\a.txt");
		Scanner sc = new Scanner (reader);
		Map map = new HashMap();
		while(sc.hasNext()){
			String s = sc.next();
			Integer n = map.get(s);
			if(n == null){
				map.put(s, 1);
			}
			else{
				map.put(s,n+1);
			}
		}
		reader.close();
		//File f1 = new File("C:\eclipse-jee-neon-3-RC3-win32-x86_64\a.txt");
		FileWriter writer = new FileWriter ("C:\eclipse-jee-neon-3-RC3-win32-x86_64\a.txt",true);
	Set  set = map.keySet();
	Iterator  a = set.iterator();
	while(a.hasNext()){
		String key = (String)a.next();
		int value = map.get(key);
		String s1 =  key +"出现了"+String.valueOf(value)+"次";
		writer.write(s1);
		writer.write("rn");
		System.out.println(key+":"+value);
	}
	writer.close();
	}
}