Java读写Properties文件
Java读写Properties文件
Java中读写资源文件最重要的类是Properties,功能大致如下：
1. 读写Properties文件
2. 读写XML文件
3. 不仅可以读写上述两类文件，还可以读写其它格式文件如txt等，只要符合key=value格式即可.
注意：资源文件中含有中文时的处理方法
1. 将中文字符通过工作转成utf8编码，可以通过Java自带的nativetoascii或Eclipse中的属性编辑器。
2. 直接调用 new String(youChineseString.getBytes("ISO-8859-1"), "GBK");
附：WEB程序中加载资源文件的方法
Properties prop = null;
1. prop = Thread.currentThread().getContextClassLoader().getResourceAsStream("filename");
2. prop = this.getClass().getClassLoader().getResourceAsStream("filename");
Properties能读取以key,value存储的任何格式文件，究竟有什么神奇，猫一眼类结构，
原来它继承了Hashtable并实现了Map接口,这样大家放心了吧。
[java] view plaincopyprint?
package apistudy;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Properties;
public class PropertiesTest
{
public static void main(String[] args)
{
String readfile = "d:" + File.separator + "readfile.properties";
String writefile = "d:" + File.separator + "writefile.properties";
String readxmlfile = "d:" + File.separator + "readxmlfile.xml";
String writexmlfile = "d:" + File.separator + "writexmlfile.xml";
String readtxtfile = "d:" + File.separator + "readtxtfile.txt";
String writetxtfile = "d:" + File.separator + "writetxtfile.txt";
readPropertiesFile(readfile); //读取properties文件
writePropertiesFile(writefile); //写properties文件
readPropertiesFileFromXML(readxmlfile); //读取XML文件
writePropertiesFileToXML(writexmlfile); //写XML文件
readPropertiesFile(readtxtfile); //读取txt文件
writePropertiesFile(writetxtfile); //写txt文件
}
//读取资源文件,并处理中文乱码
public static void readPropertiesFile(String filename)
{
Properties properties = new Properties();
try
{
InputStream inputStream = new FileInputStream(filename);
properties.load(inputStream);
inputStream.close(); //关闭流
}
catch (IOException e)
{
e.printStackTrace();
}
String username = properties.getProperty("username");
String passsword = properties.getProperty("password");
String chinese = properties.getProperty("chinese");
try
{
chinese = new String(chinese.getBytes("ISO-8859-1"), "GBK"); // 处理中文乱码
}
catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
System.out.println(username);
System.out.println(passsword);
System.out.println(chinese);
}
//读取XML文件,并处理中文乱码
public static void readPropertiesFileFromXML(String filename)
{
Properties properties = new Properties();
try
{
InputStream inputStream = new FileInputStream(filename);
properties.loadFromXML(inputStream);
inputStream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
String username = properties.getProperty("username");
String passsword = properties.getProperty("password");
String chinese = properties.getProperty("chinese"); //XML中的中文不用处理乱码，正常显示
System.out.println(username);
System.out.println(passsword);
System.out.println(chinese);
}
//写资源文件，含中文
public static void writePropertiesFile(String filename)
{
Properties properties = new Properties();
try
{
OutputStream outputStream = new FileOutputStream(filename);
properties.setProperty("username", "myname");
properties.setProperty("password", "mypassword");
properties.setProperty("chinese", "中文");
properties.store(outputStream, "author: shixing_11@sina.com");
outputStream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
//写资源文件到XML文件，含中文
public static void writePropertiesFileToXML(String filename)
{
Properties properties = new Properties();
try
{
OutputStream outputStream = new FileOutputStream(filename);
properties.setProperty("username", "myname");
properties.setProperty("password", "mypassword");
properties.setProperty("chinese", "中文");
properties.storeToXML(outputStream, "author: shixing_11@sina.com");
outputStream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
运行本程序所需的资源文件，我是放在D盘根目录，如D:/readfile.properties
1. readfile.properties
username=myname
password=mypassword
chinese=中文
2. writefile.properties
#author: shixing_11@sina.com
#Fri May 28 22:19:44 CST 2010
password=mypassword
chinese=/u4E2D/u6587
username=myname
3. readxmlfile.xml
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<entry key="password">mypassword</entry>
<entry key="chinese">中文</entry>
<entry key="username">myname</entry>
</properties>
4. writexmlfile.xml
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<comment>author: shixing_11@sina.com</comment>
<entry key="password">mypassword</entry>
<entry key="chinese">中文</entry>
<entry key="username">myname</entry>
</properties>
5. readtxtfile.txt
username=myname
password=mypassword
chinese=中文
6. writetxtfile.txt
#author: shixing_11@sina.com
#Fri May 28 22:25:16 CST 2010
password=mypassword
chinese=/u4E2D/u6587
username=myname
