Json是一種輕量級的數據交換格式，常用于前后端數據傳輸。Java自帶了許多操作Json數據的類，其中最常用的是JSONObject和JSONArray。

public class JSONObject {
public JSONObject();
public JSONObject(Map copyFrom);
public JSONObject(JSONTokener readFrom);
public JSONObject accumulate(String name, Object value);
public JSONObject append(String name, Object value) throws JSONException;
public Object get(String name);
public boolean getBoolean(String name) throws JSONException;
public double getDouble(String name) throws JSONException;
public int getInt(String name) throws JSONException;
public JSONArray getJSONArray(String name) throws JSONException;
public JSONObject getJSONObject(String name) throws JSONException;
public long getLong(String name) throws JSONException;
public String getString(String name) throws JSONException;
public boolean has(String name);
public boolean isNull(String name);
public Iterator keys();
public int length();
public JSONArray names() throws JSONException;
public JSONObject put(String name, boolean value) throws JSONException;
public JSONObject put(String name, double value) throws JSONException;
public JSONObject put(String name, int value) throws JSONException;
public JSONObject put(String name, long value) throws JSONException;
public JSONObject put(String name, Object value) throws JSONException;
public JSONObject putOnce(String name, Object value) throws JSONException;
public JSONObject putOpt(String name, Object value) throws JSONException;
public Object remove(String name);
public JSONArray toJSONArray(JSONArray names) throws JSONException;
public String toString();
public String toString(int indentFactor) throws JSONException;
public Writer write(Writer writer) throws JSONException;
}
public class JSONArray {
public JSONArray();
public JSONArray(JSONTokener readFrom);
public JSONArray(String json) throws JSONException;
public JSONArray(Collection copyFrom);
public JSONArray accumulate(Object value);
public Object get(int index);
public boolean getBoolean(int index) throws JSONException;
public double getDouble(int index) throws JSONException;
public int getInt(int index) throws JSONException;
public JSONArray getJSONArray(int index) throws JSONException;
public JSONObject getJSONObject(int index) throws JSONException;
public long getLong(int index) throws JSONException;
public String getString(int index) throws JSONException;
public boolean isNull(int index);
public Iterator iterator();
public int length();
public JSONArray put(boolean value) throws JSONException;
public JSONArray put(double value) throws JSONException;
public JSONArray put(int value) throws JSONException;
public JSONArray put(long value) throws JSONException;
public JSONArray put(Object value) throws JSONException;
public JSONArray put(int index, boolean value) throws JSONException;
public JSONArray put(int index, double value) throws JSONException;
public JSONArray put(int index, int value) throws JSONException;
public JSONArray put(int index, long value) throws JSONException;
public JSONArray put(int index, Object value) throws JSONException;
public Object remove(int index);
public JSONObject toJSONObject(JSONArray names) throws JSONException;
public String toString();
public String toString(int indentFactor) throws JSONException;
public Writer write(Writer writer) throws JSONException;
}

以上是JSONObject和JSONArray類的常用方法，使用時需要注意參數類型和異常處理。