Code片段： .properties属性文件操作工具类 & JSON工具类-白红宇

Code片段： .properties属性文件操作工具类 & JSON工具类

阅读量：5280 次

发布时间：2019-06-14

本文共 7699 字，大约阅读时间需要 25 分钟。

摘要: 原创出处:www.bysocket.com 泥瓦匠BYSocket 希望转载，保留摘要，谢谢！ “贵专” — 泥瓦匠

一、java.util.Properties API & 案例

java.util.Properties 是一个属性集合。常见的api有如下：

load(InputStream inStream) 从输入流中读取属性

getProperty(String key) 根据key，获取属性值

getOrDefault(Object key, V defaultValue) 根据key对象，获取属性值需要强转

首先在resources目录下增加/main/resources/fast.properties：

fast.framework.name=fastfast.framework.author=bysocketfast.framework.age=1

然后直接上代码PropertyUtil.java：

/** * .properties属性文件操作工具类 * * Created by bysocket on 16/7/19. */public class PropertyUtil {    private static final Logger LOGGER = LoggerFactory.getLogger(PropertyUtil.class);    /** .properties属性文件名后缀 */    public static final String PROPERTY_FILE_SUFFIX	= ".properties";    /**     * 根据属性文件名,获取属性     *     * @param propsFileName     * @return     */    public static Properties getProperties(String propsFileName) {        if (StringUtils.isEmpty(propsFileName))            throw new IllegalArgumentException();        Properties  properties  = new Properties();        InputStream inputStream = null;        try {            try {                /** 加入文件名后缀 */                if (propsFileName.lastIndexOf(PROPERTY_FILE_SUFFIX) == -1) {                    propsFileName += PROPERTY_FILE_SUFFIX;                }                inputStream = Thread.currentThread().getContextClassLoader()                        .getResourceAsStream(propsFileName);                if (null != inputStream)                    properties.load(inputStream);            } finally {                if ( null != inputStream) {                    inputStream.close();                }            }        } catch (IOException e) {            LOGGER.error("加载属性文件出错!",e);            throw new RuntimeException(e);        }        return properties;    }    /**     * 根据key,获取属性值     *     * @param properties     * @param key     * @return     */    public static String getString(Properties properties, String key){        return properties.getProperty(key);    }    /**     * 根据key,获取属性值     *     * @param properties     * @param key     * @param defaultValue     * @return     */    public static String getStringOrDefault(Properties properties, String key, String defaultValue){        return properties.getProperty(key,defaultValue);    }    /**     * 根据key,获取属性值     *     * @param properties     * @param key     * @param defaultValue     * @param 
    
          * @return     */    public static 
     
       V getOrDefault(Properties properties, String key, V defaultValue){        return (V) properties.getOrDefault(key,defaultValue);    }}

UT如下：

/** * {@link PropertyUtil} 测试用例 * 
 * Created by bysocket on 16/7/19. */public class PropertyUtilTest {    @Test    public void testGetProperties() {        Properties properties = PropertyUtil.getProperties("fast");        String fastFrameworkName = properties.getProperty("fast.framework.name");        String authorName        = properties.getProperty("fast.framework.author");        Object age               = properties.getOrDefault("fast.framework.age",10);        Object defaultVal        = properties.getOrDefault("fast.framework.null",10);        System.out.println(fastFrameworkName);        System.out.println(authorName);        System.out.println(age.toString());        System.out.println(defaultVal.toString());    }    @Test    public void testGetString() {        Properties properties = PropertyUtil.getProperties("fast");        String fastFrameworkName = PropertyUtil.getString(properties,"fast.framework.name");        String authorName        = PropertyUtil.getString(properties,"fast.framework.author");        System.out.println(fastFrameworkName);        System.out.println(authorName);    }    @Test    public void testGetOrDefault() {        Properties properties = PropertyUtil.getProperties("fast");        Object age               = PropertyUtil.getOrDefault(properties,"fast.framework.age",10);        Object defaultVal        = PropertyUtil.getOrDefault(properties,"fast.framework.null",10);        System.out.println(age.toString());        System.out.println(defaultVal.toString());    }}

Run Console:

110fastbysocket110fastbysocket

二、JACKSON 案例

首先，加个Maven 依赖:


    		
    			
     
      org.codehaus.jackson
     			
     
      jackson-mapper-asl
     			
     
      1.9.13
     		
    		
    			
     
      org.codehaus.jackson
     			
     
      jackson-jaxrs
     			
     
      1.9.13

然后直接上代码JSONUtil：

/** * JSON 工具类 * 
 * Created by bysocket on 16/7/19. */public class JSONUtil {    private static final Logger LOGGER = LoggerFactory.getLogger(JSONUtil.class);    /**     * 默认JSON类     **/    private static final ObjectMapper mapper = new ObjectMapper();    /**     * 将 Java 对象转换为 JSON 字符串     *     * @param object     * @param 
    
          * @return     */    public static 
     
       String toJSONString(T object) {        String jsonStr;        try {            jsonStr = mapper.writeValueAsString(object);        } catch (Exception e) {            LOGGER.error("Java Object Can't covert to JSON String!");            throw new RuntimeException(e);        }        return jsonStr;    }    /**     * 将 JSON 字符串转化为 Java 对象     *     * @param json     * @param clazz     * @param 
      
            * @return     */    public static 
       
         T toObject(String json, Class
        
          clazz) {        T object;        try {            object = mapper.readValue(json, clazz);        } catch (Exception e) {            LOGGER.error("JSON String Can't covert to Java Object!");            throw new RuntimeException(e);        }        return object;    }}

UT如下:

/** * {@link JSONUtil} 测试用例 * 
 * Created by bysocket on 16/7/19. */public class JSONUtilTest {    @Test    public void testToJSONString() {        JSONObject jsonObject = new JSONObject(1, "bysocket", 33);        String jsonStr = JSONUtil.toJSONString(jsonObject);        Assert.assertEquals("{\"age\":1,\"name\":\"bysocket\",\"id\":33}", jsonStr);    }    @Test(expected = RuntimeException.class)    public void testToJSONStringError() {        JSONUtil.toJSONString(System.out);    }    @Test    public void testToObject() {        JSONObject jsonObject = new JSONObject(1, "bysocket", 33);        String jsonStr = JSONUtil.toJSONString(jsonObject);        JSONObject resultObject = JSONUtil.toObject(jsonStr, JSONObject.class);        Assert.assertEquals(jsonObject.toString(), resultObject.toString());    }    @Test(expected = RuntimeException.class)    public void testToObjectError() {        JSONUtil.toObject("{int:1}", JSONObject.class);    }}class JSONObject {    int age;    String name;    Integer id;    public JSONObject() {    }    public JSONObject(int age, String name, Integer id) {        this.age = age;        this.name = name;        this.id = id;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    @Override    public String toString() {        return "JSONObject{" +                "age=" + age +                ", name='" + name + '\'' +                ", id=" + id +                '}';    }}

Run Console（抛出了异常信息）:

16/07/19 23:09:13 ERROR util.JSONUtil: JSON String Can't covert to Java Object!16/07/19 23:09:13 ERROR util.JSONUtil: Java Object Can't covert to JSON String!