思路如下：
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确定电子通讯录的文字格式，比如纯文本文件，每条通讯记录一行，每项内容之间使用tab键间隔
使用最基础的IO读写，操作此文件。
载入时从文件一行行读入，使用split拆分各项内容，存入一个对应的通讯录对象中，所有的通讯录对象保存在一个List中；
保存时，以覆盖的方式写入文件，以相同的格式写入即可。
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
public class AddList {
private String filePath = "";
private String bakPath = "";
private String content = "";
Scanner sc = new Scanner(System.in);
public String readFile(){
content = "";
if (isNull(filePath)) {
System.out.println("文件存储路径：");
filePath = sc.nextLine();
}
File file = new File(filePath);
FileReader fr = null;
try {
if (file.exists()) {
fr = new FileReader(file);
char[] chars = new char[1024];
int n = 0;
while((n = fr.read(chars)) != -1){
String string = new String(chars, 0, n);
content = content + string;
}
} else {
System.out.println("文件不存在");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fr != null) {
try {
fr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return content;
}
public void writeFile(String path){
File file = new File(path);
FileOutputStream fos = null;
mkDirs(path);
try {
fos = new FileOutputStream(file);
BufferedOutputStream bos = new BufferedOutputStream(fos);
PrintWriter pw = new PrintWriter(bos, true);
pw.print(content);
pw.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public void writeFile(){
if (isNull(filePath)) {
System.out.println("文件存储路径：");
filePath = sc.nextLine();
}
File file = new File(filePath);
FileOutputStream fos = null;
mkDirs(filePath);
try {
fos = new FileOutputStream(file);
BufferedOutputStream bos = new BufferedOutputStream(fos);
PrintWriter pw = new PrintWriter(bos, true);
pw.print(content);
pw.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public void mkDirs(String filepath){
if (filepath.indexOf("\\") != -1) {
filepath = filepath.replaceAll("\\", "/");
}
int n = filepath.indexOf("//");
String path = filepath.substring(0, n) + "//";
filepath = filepath.substring(filepath.indexOf("//") + 1, filepath.length());
String[] files = filepath.split("/");
for (int i = 0; i files.length - 1; i++) {
path = path + files[i];
File file = new File(path);
if (!file.exists()) {
file.mkdir();
}
}
}
public void addImfor(){
System.out.println("--------增加记录---------");
String name = "";
String tel = "";
String email = "";
content = readFile();
while(true){
System.out.println("姓名：");
name = sc.next();
System.out.println("电话：");
tel = sc.next();
System.out.println("Email：");
email = sc.next();
content = content + name + "" + tel + "" + email +"==";
System.out.println("0、Exit 1、继续");
int i = sc.nextInt();
if (i == 0) {
break;
}
}
writeFile();
}
public void deleteImfor(){
System.out.println("---------删除记录---------");
String name = "";
String[] imfors = null;
content = readFile();
while(true){
System.out.println("你要删除的姓名是：");
name = sc.next();
if (content.indexOf(name) != -1) {
imfors = content.split("==");
for (int i = 0; i imfors.length; i++) {
if (imfors[i].indexOf(name) != -1) {
imfors[i] = "";
}
}
具体方法如下：
1、定义封装一条记录的实体类
2、根据实际系统容量，定义一个数组
3、完成系统中显示全部记录的逻辑
4、完成系统中添加一条记录的逻辑
5、完成系统中删除一条记录的逻辑
6、完成系统中修改一条记录的逻辑
7、全部代码：
import java.util.Scanner;
class Contact {
String cellPhone;
String name;
}
public class Main {
private static void menu () {
System.out.println("************** 菜单 ******"
+ "************");
System.out.println(" 1.显示全部通讯录");
System.out.println(" 2.增加一条记录");
System.out.println(" 3.删除一条记录");
System.out.println(" 4.修改一条记录");
System.out.println(" 0.退出");
}
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
Contact[] contacts = new Contact[200];
int size = 0;
String cmd = "";
do {
menu();
System.out.print("请输入你得选择：(0-4)");
cmd = scn.nextLine();
if (cmd.equals("1")) {
if (size == 0)
System.out.println("系统当前无记录！");
else
for (int i = 0; i size; i++) {
System.out.println(contacts[i].name + ":"
+ contacts[i].cellPhone);
}
} else if (cmd.equals("2")) {
System.out.print("请输入手机号：");
String cellphone = scn.nextLine();
System.out.print("请输入姓名：");
String name = scn.nextLine();
Contact contact = new Contact();
contact.cellPhone = cellphone;
contact.name = name;
if (size contacts.length) {
contacts[size++] = contact;
System.out.println("添加成功！");
} else {
System.out.println("你最多只能添加" +
contacts.length + "条记录");
}
} else if (cmd.equals("3")) {
System.out.print("请输入要删除的手机号：");
String cellphone = scn.nextLine();
int index = -1;
for (int i = 0; i size i contacts.length;
i++) {
if (contacts[i].cellPhone.equals(cellphone)) {
index = i;
break;
}
}
if (index == -1) {
System.out.println("该记录不存在！");
} else {
for (int i = index; i size; i++) {
contacts[index] = contacts[index + 1];
}
contacts[size - 1] = null;
size--;
System.out.println("删除成功！");
}
} else if (cmd.equals("4")) {
System.out.print("请输入要修改的手机号：");
String cellphone = scn.nextLine();
int index = -1;
for (int i = 0; i size i contacts.length;
i++) {
if (contacts[i].cellPhone.equals(cellphone)) {
index = i;
break;
}
}
if (index == -1) {
System.out.println("该记录不存在！");
} else {
System.out.print("请输入姓名：");
String name = scn.nextLine();
contacts[index].name = name;
}
}
} while (!cmd.equals("0"));
System.out.println("退出成功！");
scn.close();
System.exit(0);
}
}
