读取Properties文件

     //方法一：路径写死
     public static String getPropertiesPath1(String folderpathkey) throws IOException {

        // プロパティファイル読込
        InputStream in = new BufferedInputStream(new FileInputStream("C:/Users/Hoperun/Desktop/xxxxxx.properties"));
        Properties p = new Properties();
        p.load(in);
        in.close();
        return p.getProperty(folderpathkey);
    }
     //方法二：用环境变量；
     //注意设置完环境变量后要重启电脑；
     public static String getPropertiesPath2(String folderpathkey) throws IOException {

        // プロパティファイル読込
        String commPath = System.getenv("abc.home");//创建环境变量abc.home="C:\Users\Hoperun\Desktop"
        InputStream in = new BufferedInputStream(new FileInputStream(commPath+"/xxxxxx.properties"));
        Properties p = new Properties();
        p.load(in);
        in.close();
        return p.getProperty(folderpathkey);
    }

     //方法三：在工程启动参数里面设置abc.home= C:\Users\Hoperun\Desktop

    //方法三比较常用

     public static String getPropertiesPath3(String folderpathkey) throws IOException {

        // プロパティファイル読込
     
        InputStream in = new BufferedInputStream(new FileInputStream(sysPath()+"/xxxxxx.properties"));
        Properties p = new Properties();
        p.load(in);
        in.close();
        return p.getProperty(folderpathkey);
    }

    

    public static String sysPath(){

           System.out.println(System.getProperties());

            //此处需要两个jar包：spring-core-3.2.2.RELEASE;commons-logging-1.1.3
            PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper("${", "}");
            
            //abc.home是在工程启动参数里面设置的，-Dabc.home="C:\Users\Hoperun\Desktop";此处和系统环境变量没关系；
            String configValue = helper.replacePlaceholders("${abc.home}", System.getProperties());
            
            //打印出来就是C:\Users\Hoperun\Desktop
            System.out.println(configValue);
            
            return configValue;

        }

补充知识：

        //System.getProperties() 打印出以下的结果；
         /*{java.runtime.name=Java(TM) SE Runtime Environment,
          * sun.boot.library.path=C:\Program Files\Java\jdk1.7.0_07\jre\bin,
          * java.vm.version=23.3-b01,
          * java.vm.vendor=Oracle Corporation,
          * java.vendor.url=http://java.oracle.com/,
          * path.separator=;,
          * java.vm.name=Java HotSpot(TM) Client VM, file.encoding.pkg=sun.io,
          * user.country=JP,
          * user.script=,
          * sun.java.launcher=SUN_STANDARD,
          *  sun.os.patch.level=Service Pack 1,
          *  java.vm.specification.name=Java Virtual Machine Specification,
          *  user.dir=D:\JHS_workspace_main12\ClientTest, java.runtime.version=1.7.0_07-b11,
          *  java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment,
          *  java.endorsed.dirs=C:\Program Files\Java\jdk1.7.0_07\jre\lib\endorsed,
          *  os.arch=x86,
          *  java.io.tmpdir=C:\Users\Hoperun\AppData\Local\Temp\,
          *  line.separator=java.vm.specification.vendor=Oracle Corporation, user.variant=, os.name=Windows 7, sun.jnu.encoding=MS932,
          *  java.library.path=C:\Program Files\Java\jdk1.7.0_07\jre\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jdk1.7.0_07/bin/../jre/bin/client;C:/Program Files/Java/jdk1.7.0_07/bin/../jre/bin;C:/Program Files/Java/jdk1.7.0_07/bin/../jre/lib/i386;C:\Program Files\Java\jdk1.7.0_07\bin;C:\Program Files\Java\jdk1.7.0_07\jre\bin;E:\SoftWare\eclipse_maven\eclipse;;., java.specification.name=Java Platform API Specification, java.class.version=51.0,
          *  abc.home=C:\Users\Hoperun\Desktop, sun.management.compiler=HotSpot Client Compiler, os.version=6.1,
          *  user.home=C:\Users\Hoperun, user.timezone=, java.awt.printerjob=sun.awt.windows.WPrinterJob, file.encoding=UTF-8, java.specification.version=1.7, java.class.path=D:\JHS_workspace_main12\ClientTest\build\classes;C:\apache-tomcat-7.0.41\lib\annotations-api.jar;C:\apache-tomcat-7.0.41\lib\catalina-ant.jar;C:\apache-tomcat-7.0.41\lib\catalina-ha.jar;C:\apache-tomcat-7.0.41\lib\catalina-tribes.jar;C:\apache-tomcat-7.0.41\lib\catalina.jar;C:\apache-tomcat-7.0.41\lib\ecj-4.2.2.jar;C:\apache-tomcat-7.0.41\lib\el-api.jar;C:\apache-tomcat-7.0.41\lib\jasper-el.jar;C:\apache-tomcat-7.0.41\lib\jasper.jar;C:\apache-tomcat-7.0.41\lib\jsp-api.jar;C:\apache-tomcat-7.0.41\lib\servlet-api.jar;C:\apache-tomcat-7.0.41\lib\tomcat-api.jar;C:\apache-tomcat-7.0.41\lib\tomcat-coyote.jar;C:\apache-tomcat-7.0.41\lib\tomcat-dbcp.jar;C:\apache-tomcat-7.0.41\lib\tomcat-i18n-es.jar;C:\apache-tomcat-7.0.41\lib\tomcat-i18n-fr.jar;C:\apache-tomcat-7.0.41\lib\tomcat-i18n-ja.jar;C:\apache-tomcat-7.0.41\lib\tomcat-jdbc.jar;C:\apache-tomcat-7.0.41\lib\tomcat-util.jar;D:\JHS\07-src\product\Maven\jhs-ws-service\target\jhs_service\WEB-INF\lib\dom4j-1.6.1.jar;D:\JHS\07-src\product\Maven\jhs-ws-service\target\jhs_service\WEB-INF\lib\spring-core-3.2.2.RELEASE.jar, user.name=Hoperun, java.vm.specification.version=1.7, sun.java.command=com.jhs.test.exe.ReadProperties, java.home=C:\Program Files\Java\jdk1.7.0_07\jre, sun.arch.data.model=32, user.language=ja, java.specification.vendor=Oracle Corporation, awt.toolkit=sun.awt.windows.WToolkit, java.vm.info=mixed mode, sharing, java.version=1.7.0_07, java.ext.dirs=C:\Program Files\Java\jdk1.7.0_07\jre\lib\ext;C:\Windows\Sun\Java\lib\ext, sun.boot.class.path=C:\Program Files\Java\jdk1.7.0_07\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\rt.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\sunrsasign.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_07\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_07\jre\classes, java.vendor=Oracle Corporation, file.separator=\, java.vendor.url.bug=http://bugreport.sun.com/bugreport/, sun.io.unicode.encoding=UnicodeLittle, sun.cpu.endian=little, sun.desktop=windows, sun.cpu.isalist=pentium_pro+mmx pentium_pro pentium+mmx pentium i486 i386 i86}
          */