使用Java 反射,對類中成員變量賦值.將Json對像轉為Java對像

面臨的麻煩,

Android 開發中經常需要與Intenet通信獲取數據 ,中間交換格式,大家都喜歡Json, 如何將Json對像轉為Java的對像? 一個個屬性來解析可以實現,但對我來說這樣做太土了.

通過Java的反射可以很方便,高效,易讀的實現

先看一個Json對像

{  "content":[{
 "level":1,
  "status":"2",
  "businessLicence":true,
  "hygieneLicence":true,
  "note":"note1",
  "enterprise":"free",
  "principal":"老韓",
  "phone":"13366350377",
  "time":1380862998588,
  "address":"bj aa",
  "latitude":38.112,
  "longitude":116.002
      }
,{
 "level":2,
  "status":"3",
  "businessLicence":false,
  "hygieneLicence":false,
  "note":"note22222222222222222222222",
  "enterprise":"鵬程萬裡",
  "principal":"韓工",
  "phone":"13366350377",
  "time":1380962998588,
  "address":"bj aa",
  "latitude":38.112,
  "longitude":116.002
}
,{
 "level":3,
  "status":"4",
  "businessLicence":true,
  "hygieneLicence":false,
  "note":"海天3 note333333333333333333333333333",
  "enterprise":"csdn",
  "principal":"韓工",
  "phone":"13366350377",
  "time":1380943998588,
  "address":"bj aa",
  "latitude":38.112,
  "longitude":116.002
}]
}

一個Json對像

對應的 Java對像

public class Content {

 private int level;
 private String status;
 private boolean businessLicence;
 private boolean hygieneLicence;
 private String note;//
 private String enterprise;
 private String principal;
 private long time;
 private String address;
 private double latitude;
 private double longitude;
 private String phone;

 private final String[] properties = {"level",
  "phone",
  "status",
  "businessLicence",
  "hygieneLicence",
  "note",
  "enterprise",
  "principal",
  "time",
  "address",
  "latitude",
  "longitude"
 };
 
 public Content() {
  time = System.currentTimeMillis();
  init();
 }

 public Content(JSONObject jObj) {
  if (null == jObj) {
   time = System.currentTimeMillis();
   return;
  }
  init();
  try {
   fromJSONObject(jObj);
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

 public String getCategory() {
  // TODO Auto-generated method stub
  return category;
 }

 public JSONObject toJSONObject() {
  // TODO Auto-generated method stub
  return null;
 }

 public Content fromJSONObject(JSONObject jObj) throws JSONException {
  if (null == jObj)
   return null;
  Object obj;
  for (String property : properties) {
   if (jObj.has(property)) {
    obj = jObj.get(property);

    // 方法1:
    // 比較文明,調用類的set 方法進行賦值.
    setProperty("set" + property, obj);
    // 方法2:
    // 直接對屬性賦值,有點野蠻
    // this.getClass().getDeclaredField(property).set(property, v);
    // Field field = this.getClass().getDeclaredField(property);
    // boolean accessible = field.isAccessible();
    // field.setAccessible(true);
    // field.set(this, v);
    // field.setAccessible(accessible);
   }
  }

  return this;
 }
 
 /** 下面是常用的老土的方法,全是體力活 :
  *
  */
 public Content fromJSONObject2(JSONObject jObj) throws JSONException {
  if (null == jObj)
   return null;

 
  if (jObj.has("level")) {
   level = jObj.getInt("level");
  }
  if (jObj.has("status")) {
   status = jObj.getString("status");
  }
  if (jObj.has("businessLicence")) {
   businessLicence = jObj.getBoolean("businessLicence");
  }
  if (jObj.has("hygieneLicence")) {
   hygieneLicence = jObj.getBoolean("hygieneLicence");
  }
  if (jObj.has("note")) {
   note = jObj.getString("note");
  }
  if (jObj.has("enterprise")) {
   enterprise = jObj.getString("enterprise");
  }
  if (jObj.has("principal")) {
   principal = jObj.getString("principal");
  }
  if (jObj.has("time")) {
   time = jObj.getLong("time");
  }
  if (jObj.has("address")) {
   address = jObj.getString("address");
  }
  if (jObj.has("latitude")) {
   latitude = jObj.getDouble("latitude");
  }
  if (jObj.has("longitude")) {
   longitude = jObj.getDouble("longitude");
  }
  return this;
 }

 public int getLevel() {
  return level;
 }

 public void setLevel(int level) {
  this.level = level;
 }

 public String getStatus() {
  return status;
 }

 public void setStatus(String status) {
  this.status = status;
 }

 public boolean isBusinessLicence() {
  return businessLicence;
 }

 public void setBusinessLicence(boolean businessLicence) {
  this.businessLicence = businessLicence;
 }

 public boolean isHygieneLicence() {
  return hygieneLicence;
 }

 public void setHygieneLicence(boolean hygieneLicence) {
  this.hygieneLicence = hygieneLicence;
 }

 public String getNote() {
  return note;
 }

 public void setNote(String note) {
  this.note = note;
 }

 public String getEnterprise() {
  return enterprise;
 }

 public void setEnterprise(String enterprise) {
  this.enterprise = enterprise;
 }

 public String getPrincipal() {
  return principal;
 }

 public void setPrincipal(String principal) {
  this.principal = principal;
 }

 public long getTime() {
  return time;
 }

 public void setTime(long time) {
  this.time = time;
 }

 public String getAddress() {
  return address;
 }

 public void setAddress(String address) {
  this.address = address;
 }

 public double getLatitude() {
  return latitude;
 }

 public void setLatitude(double latitude) {
  this.latitude = latitude;
 }

 public double getLongitude() {
  return longitude;
 }

 public void setLongitude(double longitude) {
  this.longitude = longitude;
 }

 boolean isMe(String category) {
  this.category.equals(category);
 }

 public String getContent() {
  return note;
 }

 public Drawable getIcon() {
  return null;
 }

 String getVillage() {
  return null;
 }

 public String getCell() {
  return null;
 }

 public String getPhone() {
  return phone;
 }

 public void setPhone(String phone) {
  this.phone = phone;
 }

 // 反射代碼,
 final private Map<String, Method> methodMap = new HashMap<String, Method>();// 以set開始的方法的map
                    // 可以直接獲取需要的set方法.

 protected void init() {
  Class<?> userClass = this.getClass();// Class.forName(this.getClass()); 加載類
  Method[] methods = userClass.getDeclaredMethods();// 獲得類的方法集合
  for (int i = 0; i < methods.length; i++) {
   if (methods[i].getName().startsWith("set")) {
    methodMap.put(methods[i].getName().toLowerCase(), methods[i]);

   }
  }

 }

 protected void setProperty(String property, Object v) {
  Method method = methodMap.get(property.toLowerCase());
 
  try {
   method.invoke(this, v);
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

}

對通上述的代碼,可以明顯發現,使用Java 反射帶來的好處