Java-Properties文件读取工具类

 import org.apache.commons.configuration.ConfigurationException;
 import org.apache.commons.configuration.PropertiesConfiguration;

 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONObject;

 /**
  * @ClassName: ReadPropertiesUtil
  */
 public class ReadPropertiesUtil {
     // 声明配置文件
     private static String[] confProps = { "config.properties" };
     private static PropertiesConfiguration conf = null;

     /**
      * 获取所有配置对象
      */
     public static PropertiesConfiguration getConf() {
         conf = new PropertiesConfiguration();// 初始化对象
         /* 把所有props配置文件一次加载,共后续使用 */
         for (int i = 0; i < confProps.length; i++) {
             try {
                 conf.load(confProps[i]);
             } catch (ConfigurationException e) {
                 conf = null;
             }
         }
         return conf;
     }

     /*
      * PropsUtil getInt()
      */
     public static Integer getInt(String key) {
         /** 声明返回值 **/
         Integer value = null;
         try {
             /* 获取value值 */
             conf = getConf();
             value = conf.getInt(key);
         } catch (Exception e) {
         }
         return value;
     }

     /*
      * PropsUtil getString()
      */
     public static String getString(String key) {
         /** 声明返回值 **/
         String value = null;
         try {
             /* 获取value值 */
             conf = getConf();
             value = conf.getString(key);
         } catch (Exception e) {
         }
         return value;
     }

     /*
      * PropsUtil getLong()
      */
     public static Long getLong(String key) {
         /** 声明返回值 **/
         Long value = null;
         try {
             /* 获取value值 */
             conf = getConf();
             value = conf.getLong(key);
         } catch (Exception e) {
         }
         return value;
     }

     /*
      * PropsUtil getBoolean()
      */
     public static boolean getBoolean(String key) {
         /** 声明返回值 **/
         boolean value = true;
         try {
             /* 获取value值 */
             conf = getConf();
             value = conf.getBoolean(key);
         } catch (Exception e) {
             value = false;
         }
         return value;
     }

     /*
      * PropsUtil getList()
      */
     public static String[] getStringArray(String key) {
         /** 声明返回值 **/
         String[] value = null;
         try {
             /* 获取value值 */
             conf = getConf();
             value = conf.getStringArray(key);
         } catch (Exception e) {
         }
         return value;
     }

     /*
      * PropsUtil getJsonHeaders()
      */
     public static JSONObject getJsonHeaders(String key) {
         JSONObject json = null;// 声明返回值
         try {
             /** 解析*.Properties文件 **/
             conf = getConf();
             String value = conf.getString(key).replace("=", ",");
             json = JSON.parseObject(value);
         } catch (Exception e) {
         }
         return json;
     }

     public static void main(String[] args) throws Exception {

         System.out.println(getString("dbcp.url"));

         // String[] tmp = getStringArray("Email_to");
         // for(String to:tmp){
         // System.out.println(to);
         // }

         // JSONObject json = getJsonHeaders("httpHead");
         // for(Entry<String, Object> entry:json.entrySet()){
         // System.out.println(entry.getKey() + "-----" + entry.getValue().toString());
         // }

         // System.out.println(getInt("dbcp.url"));

         // System.out.println(getInt("redis.minIdle"));
         // String[] tmp = getStringArray("redis.redisSlaveIp");
         // for(int i=0;i<tmp.length;i++){
         // System.out.println(tmp[i].split(":")[0]);
         // System.out.println(tmp[i].split(":")[1]);
         // }
     }
 }

 //相关依赖
         <!-- commons-configuration -->
         <dependency>
             <groupId>commons-configuration</groupId>
             <artifactId>commons-configuration</artifactId>
             <version>1.9</version>
         </dependency>
         <!-- fastjson json -->
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
             <version>1.2.7</version>
         </dependency>

Properties文件载入工具类:

　　依赖spring等。

　　

         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
             <version>1.7.7</version>
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-log4j12</artifactId>
             <version>1.7.7</version>
         </dependency>

 import java.io.IOException;
 import java.io.InputStream;
 import java.util.NoSuchElementException;
 import java.util.Properties;

 import org.apache.commons.io.IOUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;

 /**
  * Properties文件载入工具类. 可载入多个properties文件,
  * 相同的属性在最后载入的文件中的值将会覆盖之前的值，但以System的Property优先.
  */
 public class PropertiesLoader {
     private static Logger logger = LoggerFactory.getLogger(PropertiesLoader.class);
     private static ResourceLoader resourceLoader = new DefaultResourceLoader();
     private final Properties properties;

     public PropertiesLoader(String... resourcesPaths) {
         properties = loadProperties(resourcesPaths);
     }

     public Properties getProperties() {
         return properties;
     }

     /**
      * 取出Boolean类型的Property，但以System的Property优先.如果都为Null抛出异常,如果内容不是true/false则返回false.
      */
     public Boolean getBoolean(String key) {
         String value = getValue(key);
         if (value == null) {
             throw new NoSuchElementException();
         }
         return Boolean.valueOf(value);
     }

     /**
      * 取出Boolean类型的Property，但以System的Property优先.如果都为Null则返回Default值,如果内容不为true/false则返回false.
      */
     public Boolean getBoolean(String key, boolean defaultValue) {
         String value = getValue(key);
         return value != null ? Boolean.valueOf(value) : defaultValue;
     }

     /**
      * 取出Double类型的Property，但以System的Property优先.如果都为Null或内容错误则抛出异常.
      */
     public Double getDouble(String key) {
         String value = getValue(key);
         if (value == null) {
             throw new NoSuchElementException();
         }
         return Double.valueOf(value);
     }

     /**
      * 取出Double类型的Property，但以System的Property优先.如果都为Null则返回Default值，如果内容错误则抛出异常
      */
     public Double getDouble(String key, Integer defaultValue) {
         String value = getValue(key);
         return value != null ? Double.valueOf(value) : defaultValue;
     }

     /**
      * 取出Integer类型的Property，但以System的Property优先.如果都为Null或内容错误则抛出异常.
      */
     public Integer getInteger(String key) {
         String value = getValue(key);
         if (value == null) {
             throw new NoSuchElementException();
         }
         return Integer.valueOf(value);
     }

     /**
      * 取出Integer类型的Property，但以System的Property优先.如果都为Null则返回Default值，如果内容错误则抛出异常
      */
     public Integer getInteger(String key, Integer defaultValue) {
         String value = getValue(key);
         return value != null ? Integer.valueOf(value) : defaultValue;
     }

     /**
      * 取出String类型的Property，但以System的Property优先,如果都为Null则抛出异常.
      */
     public String getProperty(String key) {
         String value = getValue(key);
         if (value == null) {
             throw new NoSuchElementException();
         }
         return value;
     }

     /**
      * 取出String类型的Property，但以System的Property优先.如果都为Null则返回Default值.
      */
     public String getProperty(String key, String defaultValue) {
         String value = getValue(key);
         return value != null ? value : defaultValue;
     }

     /**
      * 取出Property，但以System的Property优先,取不到返回空字符串.
      */
     private String getValue(String key) {
         String systemProperty = System.getProperty(key);
         if (systemProperty != null) {
             return systemProperty;
         }
         if (properties.containsKey(key)) {
             return properties.getProperty(key);
         }
         return "";
     }

     /**
      * 载入多个文件, 文件路径使用Spring Resource格式.
      */
     private Properties loadProperties(String... resourcesPaths) {
         Properties props = new Properties();
         for (String location : resourcesPaths) {
             InputStream is = null;
             try {
                 Resource resource = resourceLoader.getResource(location);
                 is = resource.getInputStream();
                 props.load(is);
             } catch (IOException ex) {
                 logger.info("Could not load properties from path:" + location + ", " + ex.getMessage());
             } finally {
                 IOUtils.closeQuietly(is);
             }
         }
         return props;
     }
 }