properties配置文件操作实例

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class FileSystemPropertyTest
{

public static Properties initProperties(String path) throws Exception
{
Properties prop = new Properties();
InputStream is = null;
try
{
is = new FileInputStream(path);
prop.load(is);
}
catch (FileNotFoundException e)
{
throw e;
}
catch (IOException e)
{
throw e;
}
finally
{
try
{
if (is != null)
{
is.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}

}
return prop;
}

public static void main(String[] args) throws Exception
{
String filePath="c:"+File.separator+"test"+File.separator+"test.properties";
Properties prop = initProperties(filePath);
System.out.println(prop.getProperty("name"));
System.out.println(prop.getProperty("age"));
}
}

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;
public class TestMain {

//根据key读取value
public static String readValue(String filePath,String key) {
Properties props = new Properties();
try {
InputStream in = new BufferedInputStream (new FileInputStream(filePath));
props.load(in);
String value = props.getProperty (key);
System.out.println(key+value);
return value;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}

//读取properties的全部信息
public static void readProperties(String filePath) {
Properties props = new Properties();
try {
InputStream in = new BufferedInputStream (new FileInputStream(filePath));
props.load(in);
Enumeration en = props.propertyNames();
while (en.hasMoreElements()) {
String key = (String) en.nextElement();
String Property = props.getProperty (key);
System.out.println(key+Property);
}
} catch (Exception e) {
e.printStackTrace();
}
}
//写入properties信息
public static void writeProperties(String filePath,String parameterName,String parameterValue) {
Properties prop = new Properties();
try {
InputStream fis = new FileInputStream(filePath);
//从输入流中读取属性列表（键和元素对）
prop.load(fis);
//调用 Hashtable 的方法 put。使用 getProperty 方法提供并行性。
//强制要求为属性的键和值使用字符串。返回值是 Hashtable 调用 put 的结果。
OutputStream fos = new FileOutputStream(filePath);
prop.setProperty(parameterName, parameterValue);
//以适合使用 load 方法加载到 Properties 表中的格式，
//将此 Properties 表中的属性列表（键和元素对）写入输出流
prop.store(fos, "Update '" + parameterName + "' value");
} catch (IOException e) {
System.err.println("Visit "+filePath+" for updating "+parameterName+" value error");
}
}
public static void main(String[] args) {
readValue("info.properties","url");
writeProperties("info.properties","age","21");
readProperties("info.properties" );
System.out.println("OK");
}
}