java-初识Properties

我就是我 2021-12-15 01:07 340阅读 0赞

**1.通过代码了解一哈:**

1 package com.etc;
     2 
     3 import java.io.File;
     4 import java.io.FileInputStream;
     5 import java.io.FileNotFoundException;
     6 import java.io.FileOutputStream;
     7 import java.io.IOException;
     8 import java.util.Properties;
     9 /*
    10  * 作用:读写资源配置文件
    11  * 方法:
    12  * 1.存取方法
    13  * setProperty(String key,String value);键与值只能为字符串
    14  * getProperty(String key);存在则返回值，不存在返回空
    15  * getProperty(String key,defaultValue);如果不存在返回默认值defaultValue
    16  * 2.存储到文件中
    17  * (1)生成的文件后缀名为.properties;
    18  * store(OutputStream out,String comments);
    19  * store(Writer writer,String comments);
    20  * (2)生成的文件后缀名为.xml
    21  * storeToXML(OutputStream out,String comments);默认UTF-8字符集
    22  * storeToXML(OutputStream out,String comments，String encoding);指定字符集
    23  * 3.从文件中读取内容
    24  * (1).properties文件读取
    25  * load(InputStream inStream);
    26  * load(Reader reader)
    27  * (2).xml文件读取
    28  * loadFromXML(InputStream inStream)
    29  * 4.相对路径与绝对路径：
    30  * 相对路径:当前项目，工程
    31  * 绝对路径:具体盘符
    32  * 5.类路径加载资源文件
    33  * 类所在的根路径uri:
    34  * (1)类名.class.getResourceAsStream("/uri");
    35  * (2)Thread.currentThread().getContextClassLoader().getResourceAsStream("/uri");
    36  */
    37 public class TestProperties {
    38 
    39     public static void main(String[] args) throws FileNotFoundException, IOException {
    40 
    41         //利用Properties存取信息，以后可以用来改进连接数据库的方法，提高效率
    42         Properties pro=new Properties();
    43         //注册驱动
    44         pro.setProperty("driver", "com.mysql.jdbc.Driver");
    45         //获取连接:url:jdbc:mysql://连接主机IP:端口号/数据库名字
    46         pro.setProperty("url", "jdbc:mysql://localhost:3306/TEST");
    47         //用户名与密码
    48         pro.setProperty("password", "121515");
    49         pro.setProperty("user", "root");
    50         //获取value
    51         System.out.println(pro.getProperty("url","空"));
    52         System.out.println(pro.getProperty("test","空"));
    53         //存储到桌面
    54         pro.store(new FileOutputStream(new File("C:/Users/Administrator/Desktop/文件1.properties")), "ABC");
    55         pro.storeToXML(new FileOutputStream(new File("C:/Users/Administrator/Desktop/文件2.xml")), "测试文件","GBK");
    56         pro.storeToXML(new FileOutputStream(new File("文件3.xml")), "测试文件","GBK");
    57         
    58         //从存储文件中获取信息并存入pro2对象中
    59         Properties pro2=new Properties();
    60         pro2.load(new FileInputStream (new File("C:/Users/Administrator/Desktop/文件1.properties")));
    61         System.out.println("文件读取内容为:"+pro2.getProperty("url")); 
    62     }
    63 
    64 }

**2.效果截图:**

控制台输出**:**

**![1532279-20190428144126828-1382651844.png][]**

项目：

![1532279-20190428144147328-1705648616.png][]

![1532279-20190428144201071-1527720379.png][]

桌面：

![1532279-20190428144220948-1949035648.png][]

打开文件:

![1532279-20190428144236278-1006491090.png][]

![1532279-20190428144250333-539116455.png][]

**接下来利用面向对象的理念实现一个教师信息写入文件的小案例：**

1.新建一个实体类，用于存放数据

1 package com.test;
     2 //实体类用于存放数据
     3 public class Teacher {
     4     private String name;
     5     private int id;
     6     private String date;
     7 
     8     public Teacher(String name, int id, String date) {
     9         super();
    10         this.name = name;
    11         this.id = id;
    12         this.date = date;
    13     }
    14     public String getName() {
    15         return name;
    16     }
    17     public void setName(String name) {
    18         this.name = name;
    19     }
    20     public int getId() {
    21         return id;
    22     }
    23     public void setId(int id) {
    24         this.id = id;
    25     }
    26     public String getDate() {
    27         return date;
    28     }
    29     public void setDate(String date) {
    30         this.date = date;
    31     }
    32     @Override
    33     public String toString() {
    34         return  "姓名:"+name+" 编号:"+id+" 入教时间:"+date;
    35     }
    36 
    37 }

2.测试类，场景模拟

1 package com.test;
     2 
     3 import java.io.File;
     4 import java.io.FileInputStream;
     5 import java.io.FileNotFoundException;
     6 import java.io.FileOutputStream;
     7 import java.io.IOException;
     8 import java.util.Properties;
     9 
    10 /*
    11  * 简单运用面向对象实现教师信息写入配置文件加以保存
    12  * 总共分为两步:
    13  * 1.输入数据
    14  * 2.处理数据并将其存储在桌面的文件下
    15  */
    16 public class teacherInfoWriteIn {
    17 
    18     public static void main(String[] args) throws FileNotFoundException, IOException {
    19         //获取数据并将数据存取至桌面的文件1.xml文件中
    20         Properties pro=setData();
    21         pro.storeToXML(new FileOutputStream(new File("C:/Users/Administrator/Desktop/Test1.xml")), "教师信息表","GBK");
    22         //将桌面上的文件1里面的信息获取出来
    23         Properties pro2=new Properties();
    24         pro2.loadFromXML(new FileInputStream(new File("C:/Users/Administrator/Desktop/Test1.xml")));
    25         System.out.println(pro2.getProperty("张老师信息"));
    26         System.out.println(pro2.getProperty("李老师信息"));
    27         System.out.println(pro2.getProperty("王老师信息"));
    28         System.out.println(pro2.getProperty("刘老师信息"));
    29     }
    30     //数据初始化输入
    31     public  static Properties setData() {
    32         Properties pro=new Properties();
    33         Teacher t1=new Teacher("张三",11152,"2004-5");
    34         Teacher t2=new Teacher("李四",13157,"2007-4");
    35         Teacher t3=new Teacher("王五",12456,"1998-5");
    36         Teacher t4=new Teacher("刘六",15478,"1999-5");
    37         pro.put("张老师信息",t1.toString());
    38         pro.put("李老师信息",t2.toString());
    39         pro.put("王老师信息",t3.toString());
    40         pro.put("刘老师信息",t4.toString());
    41         return pro;
    42     }
    43 }

**效果截图:**

**控制台:**

**![1532279-20190428183911533-224183133.png][]**

**桌面：**

**![1532279-20190428172404622-250521775.png][]**

ps:文章待完善，先简单了解学习一下，如有问题欢迎大佬指点。

转载于:https://www.cnblogs.com/weekstart/p/10782730.html

[1532279-20190428144126828-1382651844.png]: /images/20211214/089989bd928046358556fcda69554a02.png
[1532279-20190428144147328-1705648616.png]: /images/20211214/d2a478b5ff424c3bb89bbd4e1c9224a0.png
[1532279-20190428144201071-1527720379.png]: /images/20211214/641de265b13d41aeb7a91e885e785dca.png
[1532279-20190428144220948-1949035648.png]: /images/20211214/4ade5ad7eeb44ee19e235e2cf4d9a519.png
[1532279-20190428144236278-1006491090.png]: /images/20211214/41b44645c5a740f6806e4e18ddd57d9c.png
[1532279-20190428144250333-539116455.png]: /images/20211214/6b19ece1021b45f383856b4a65ad8ac8.png
[1532279-20190428183911533-224183133.png]: /images/20211214/ff0a1c4205fb4f9c8732fdb80f0b647d.png
[1532279-20190428172404622-250521775.png]: /images/20211214/78922da6d4884367bf0f280906503432.png