输出输入流的问题

这个问题要分为几个核心部分：
1.读写文件package file;import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;public class FileOperation { /**
* 读取配置文件
*
* @param path
* @return 配置文件属性值
* @throws IOException
*/
public Properties getProperties(String path) throws IOException {
InputStream inputStream = this.getClass().getClassLoader()
.getResourceAsStream(path);
Properties p = new Properties();
p.load(inputStream);
return p;
} /**
* 读取文件，以List形式存储
* @param path
* @return
* @throws IOException
*/
public List<String> getReadLine(String path) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(
new FileInputStream(path)));
String strLine = "";
List<String> list = new ArrayList();
while((strLine = br.readLine())!=null)
{
list.add(strLine);
}
br.close();
return list;
}

/**
* 写文件，指定文件路径和文件内容,文件加载在原有文件内容后面
* @param content
* @param path
* @throws IOException
*/
public void writeFile(String content,String path) throws IOException{
FileWriter fw = new FileWriter(path,true);
fw.write(content,0,content.length());
fw.write("\r\n");
fw.flush();
fw.close();
}

public static void main(String[] args) throws IOException {
FileOperation file = new FileOperation();
Properties p = file.getProperties("config.properties");
System.out.println(p.getProperty("step"));
System.out.println(p.getProperty("base"));

System.out.println();
}
}这是我在某次实验的代码，估计你能搞得懂。2.就是文件的操作（主要是文件的移动，适用于各种操作系统，你要做的事是修改路径）：package file;
import java.io.File;public class FileMove { /**
* 功能描述：创建path目录及其父目录 
*
* @param path
* @author helloc 
* 时间：2009-10-22 下午05:01:33 
*/
public void createFolder(String path) {
try {
File file = new File(path);
if (!file.exists()) {
file.mkdirs();
}
} catch (Exception e) {
System.out.println("创建文件夹出错");
e.printStackTrace();
}
} /**
* 功能描述：把filename从from文件夹移动到to文件夹 
*
* @param from
* @param to
* @author helloc 
* 时间：2009-10-22 下午05:08:21 
*/
public void removeFromTo(String from, String to, String filename) {
createFolder(to);
File file = new File(from, filename);
if (file.isFile()) {
System.out.println("移动" + filename);
file.renameTo(new File(to, file.getName()));
} else {
System.out.println(filename + "不存在");
}
} public static void main(String[] args) {
String from = "e:\\job\\workspace_helloc\\DYFY\\WebRoot\\userfile\\";
String to = "e:\\job\\workspace_helloc\\DYFY\\WebRoot\\userfile\\200910\\";
new FileMove().removeFromTo(from, to,
"0a5da70100af416c869bdbfea10828ff.jpg");
}
}这段代码是参考网上的一段代码，你仔细看一看，针对文件操作类做一下功课相信你能轻松搞定你的问题。
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Scanner;public class Test {
public static void main(String[] args) {
//根据输入的学生人new学生数组
Scanner input = new Scanner(System.in);
System.out.println("请输入学生人数:");
int num = input.nextInt();
Student[] students = new Student[num];

//调用输入方法输入学生信息
read(students);

//写入信息到文件
try {
writeToFile(students);
} catch (IOException e) {
System.out.println("写入文件错误！");
return;
}

//复制文件A.txt到B.txt
try {
copy();
} catch (IOException e) {
System.out.println("复制文件出错！");
}

//清空数组，从文件B读入学生信息
students = new Student[num];
try {
readFromFile(students);
} catch (IOException e) {
System.out.println("读取文件错误！");
}

//打印学生信息
print(students);
}

private static void readFromFile(Student[] students) throws IOException {
File in = new File("d:\\B.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(in)));
String temp = "";
temp = br.readLine();
int num = 0;
while((null != temp || !"".equals("")) && (num < students.length)) {
String[] arr = temp.split(";");
Student stu = new Student();
String str = "";
for(int i=0; i<arr.length; i++) {
str = arr[i];
int index = str.indexOf(":") + 1;
if(str.startsWith("姓名"))
stu.setName(str.substring(index));
else if(str.startsWith("学号"))
stu.setNo(str.substring(index));
else if(str.startsWith("年龄"))
stu.setAge(Integer.parseInt(str.substring(index)));
else if(str.startsWith("身份证号"))
stu.setId(str.substring(index));
else if(str.startsWith("成绩:"))
stu.setScore(Float.parseFloat(str.substring(index)));
}
students[num++] = stu;
temp = br.readLine();
}
br.close();
}

/**
* 复制文件"d:\\A.txt"到"d:\\B.txt"
* @throws IOException 复制文件出错时抛出IO异常
*/
private static void copy() throws IOException {
File in = new File("d:\\A.txt");
File out = new File("d:\\B.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(in)));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(out)));
String temp = br.readLine();
while(null != temp || !"".equals("")) {
bw.write(temp);
bw.newLine();//换一行
temp = br.readLine();
}
bw.close();
br.close();
}

/**
* 将学生信息写入文件"d:\\A.txt"，每个学生的信息占一行
* @param students 要写入文件的学生信息数组
* @throws IOException 写文件出错时抛出IO异常
*/
private static void writeToFile(Student[] students) throws IOException {
File f = new File("d:\\A.txt");
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(f)));
for(int i=0; i<students.length; i++) {
bw.write(students[i].toString());
bw.newLine();//换一行
}
bw.close();
}

/**
* 打印学生信息
* @param students 要打印的学生数组
*/
private static void print(Student[] students) {
for(Student stu : students) {
System.out.println(stu);
}
}

/**
* 输入n个学生的信息
* @param students 保存学生信息的数组
*/
private static void read(Student[] students) {
Scanner input = new Scanner(System.in);
for(int i=0; i<students.length; i++) {
System.out.println("请输入一个学生的信息，用空格分隔，输入顺序是,学号姓名年龄身份证号成绩:");
Student stu = new Student();
stu.setNo(input.next());
stu.setName(input.next());
stu.setAge(input.nextInt());
stu.setId(input.next());
stu.setScore(input.nextFloat());
students[i] = stu;
}
}
}class Student {
private String no;
private String name;
private int age;
private String id;
private float score; public String getNo() {
return no;
} public void setNo(String no) {
this.no = no;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} public String getId() {
return id;
} public void setId(String id) {
this.id = id;
} public float getScore() {
return score;
} public void setScore(float score) {
this.score = score;
}

/**
* 重写toString方法，方便文件操作和打印学生信息时要用到
*/
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("学号:" + no + ";姓名:" + name + ";身份证号:" + id + ";成绩:" + score + ";年龄:" + age);
return sb.toString();
}
}
public class Student implements Serializable {
private String no;
private int age;
private String id;
private String name;
private Map scores;
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getNo() {
return no;
}
public void setNo(String no) {
this.no = no;
}
public Map getScores() {
return scores;
}
public void setScores(Map scores) {
this.scores = scores;
}
public String toString() {
StringBuffer bs = new StringBuffer();
bs.append(this.no);
bs.append(",");
bs.append(this.name);
bs.append(",");
bs.append(this.age);
bs.append(",");
bs.append(this.id);
bs.append(",");
Set set = this.scores.entrySet();
for(Iterator it = set.iterator();it.hasNext();){
Entry entry = (Entry) it.next();
bs.append(entry.getKey()+"@"+entry.getValue());
bs.append("#");
}
return bs.substring(0, bs.length()-1);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
================public class Test{
public static void main(String[] args) throws Exception{
Student[] students = new Student[3];
readData(students);
writeData(students);
}
private static void readData(Student[] students){
Scanner s = new Scanner(System.in);
//输入格式学号,姓名,年龄,身份证号,课程名@分数#课程名@分数;,,,课程名@分数#课程名@分数;,,,课程名@分数#课程名@分数
//1,name1,20,123456,数学@90#语文@80;2,name2,21,1234567,数学@80#语文@90;3,name3,20,12345678,数学@91#语文@79
/*while(s.hasNext()){
String line = s.nextLine();
System.out.println(line);
}*/
String line = s.nextLine();
String[] student = line.split(";");
for(int i = 0;i<student.length;i++){
String[] stu = student[i].split(",");
Student aStudent = new Student();
aStudent.setNo(stu[0]);
aStudent.setName(stu[1]);
aStudent.setAge(Integer.parseInt(stu[2]));
aStudent.setId(stu[3]);
Map scores = new HashMap();
String[] score = stu[4].split("#");
for(int j=0;j<score.length;j++){
String[] keyValue = score[j].split("@");
scores.put(keyValue[0],keyValue[1]);
}
aStudent.setScores(scores);
students[i] = aStudent;
}
}
private static void writeData(Student[] students) throws IOException, ClassNotFoundException{
File f = new File("c:\\student.txt");
if(!f.exists()){
f.createNewFile();
}
OutputStream os = new FileOutputStream(f);
ObjectOutput oo = new ObjectOutputStream(os);
oo.writeObject(students);
oo.close();
os.close();
copyAndShow(f);
}
private static void copyAndShow(File f) throws IOException, ClassNotFoundException{
InputStream is = new FileInputStream(f);
ObjectInput oi = new ObjectInputStream(is);
File ff = new File("c:\\student1.txt");
if(!ff.exists()){
ff.createNewFile();
}
OutputStream os = new FileOutputStream(ff);
ObjectOutput oo = new ObjectOutputStream(os);
Object obj = oi.readObject();
oo.writeObject(obj);
oo.close();
os.close();
oi.close();
is.close();
is = new FileInputStream(ff);
oi = new ObjectInputStream(is);
Student[] students = (Student[]) oi.readObject();
for(int i = 0;i<students.length;i++){
Student student = students[i];
System.out.println(student);
}
}}
代码不是很严谨..........

调试易

输出输入流的问题

解决方案 »