本文整理了Java中org.json.JSONObject.opt()方法的一些代码示例，展示了JSONObject.opt()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。JSONObject.opt()方法的具体详情如下：
包路径：org.json.JSONObject
类名称：JSONObject
方法名：opt

JSONObject.opt介绍

[英]Returns the value mapped by name, or null if no such mapping exists.
[中]返回按名称映射的值，如果不存在此类映射，则返回null。

代码示例

代码示例来源：origin: zzz40500/GsonFormat

/**
 * Get an optional JSONObject associated with a key. It returns null if
 * there is no such key, or if its value is not a JSONObject.
 *
 * @param key
 *            A key string.
 * @return A JSONObject which is the value.
 */
public JSONObject optJSONObject(String key) {
  Object object = this.opt(key);
  return object instanceof JSONObject ? (JSONObject) object : null;
}

代码示例来源：origin: zzz40500/GsonFormat

/**
 * Get an optional JSONArray associated with a key. It returns null if there
 * is no such key, or if its value is not a JSONArray.
 *
 * @param key
 *            A key string.
 * @return A JSONArray which is the value.
 */
public JSONArray optJSONArray(String key) {
  Object o = this.opt(key);
  return o instanceof JSONArray ? (JSONArray) o : null;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is a {@code
 * JSONArray}. Returns null otherwise.
 */
public JSONArray optJSONArray(String name) {
  Object object = opt(name);
  return object instanceof JSONArray ? (JSONArray) object : null;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is a {@code
 * JSONObject}. Returns null otherwise.
 */
public JSONObject optJSONObject(String name) {
  Object object = opt(name);
  return object instanceof JSONObject ? (JSONObject) object : null;
}

代码示例来源：origin: apache/geode

/**
 * Returns the value mapped by {@code name} if it exists and is a {@code
 * JSONArray}, or null otherwise.
 *
 * @param name The name of the field we want.
 * @return The value of the specified field (assuming it is a JSNOArray
 */
public JSONArray optJSONArray(String name) {
 Object object = opt(name);
 return object instanceof JSONArray ? (JSONArray) object : null;
}

代码示例来源：origin: apache/geode

/**
 * Returns the value mapped by {@code name} if it exists and is a {@code
 * JSONObject}, or null otherwise.
 *
 * @param name The name of the value we want.
 * @return The specified value.
 */
public JSONObject optJSONObject(String name) {
 Object object = opt(name);
 return object instanceof JSONObject ? (JSONObject) object : null;
}

代码示例来源：origin: alibaba/Tangram-Android

public Object optParam(String key) {
  if (extras.has(key)) {
    return extras.opt(key);
  }
  if (style != null && style.extras != null) {
    return style.extras.opt(key);
  }
  return null;
}

代码示例来源：origin: zzz40500/GsonFormat

/**
 * Determine if the value associated with the key is null or if there is no
 * value.
 *
 * @param key
 *            A key string.
 * @return true if there is no value associated with the key or if the value
 *         is the JSONObject.NULL object.
 */
public boolean isNull(String key) {
  return JSONObject.NULL.equals(this.opt(key));
}

代码示例来源：origin: zzz40500/GsonFormat

/**
 * Get an optional string associated with a key. It returns the defaultValue
 * if there is no such key.
 *
 * @param key
 *            A key string.
 * @param defaultValue
 *            The default.
 * @return A string which is the value.
 */
public String optString(String key, String defaultValue) {
  Object object = this.opt(key);
  return NULL.equals(object) ? defaultValue : object.toString();
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is a long or
 * can be coerced to a long. Returns {@code fallback} otherwise. Note that JSON represents
 * numbers as doubles, so this is <a href="#lossy">lossy</a>; use strings to transfer
 * numbers via JSON.
 */
public long optLong(String name, long fallback) {
  Object object = opt(name);
  Long result = JSON.toLong(object);
  return result != null ? result : fallback;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is a boolean or
 * can be coerced to a boolean. Returns {@code fallback} otherwise.
 */
public boolean optBoolean(String name, boolean fallback) {
  Object object = opt(name);
  Boolean result = JSON.toBoolean(object);
  return result != null ? result : fallback;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is an int or
 * can be coerced to an int. Returns {@code fallback} otherwise.
 */
public int optInt(String name, int fallback) {
  Object object = opt(name);
  Integer result = JSON.toInteger(object);
  return result != null ? result : fallback;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists and is a double or
 * can be coerced to a double. Returns {@code fallback} otherwise.
 */
public double optDouble(String name, double fallback) {
  Object object = opt(name);
  Double result = JSON.toDouble(object);
  return result != null ? result : fallback;
}

代码示例来源：origin: robovm/robovm

/**
 * Returns the value mapped by {@code name} if it exists, coercing it if
 * necessary. Returns {@code fallback} if no such mapping exists.
 */
public String optString(String name, String fallback) {
  Object object = opt(name);
  String result = JSON.toString(object);
  return result != null ? result : fallback;
}

代码示例来源：origin: alibaba/Tangram-Android

private void parseBizParams(BaseCell cell, JSONObject json) {
  if (json == null) {
    return;
  }
  Iterator<String> iterator = json.keys();
  while (iterator.hasNext()) {
    String key = iterator.next();
    cell.addBizParam(key, json.opt(key));
  }
}

代码示例来源：origin: apache/geode

public GfJsonObject getJSONObject(String key) {
 Object opt = jsonObject.opt(key);
 if (opt instanceof GfJsonObject) {
  return (GfJsonObject) opt;
 }
 if (opt == null) {
  return null;
 }
 return new GfJsonObject(opt);
}

代码示例来源：origin: facebook/facebook-android-sdk

static boolean jsonObjectContainsValue(JSONObject jsonObject, Object value) {
  @SuppressWarnings("unchecked")
  Iterator<String> keys = jsonObject.keys();
  while (keys.hasNext()) {
    Object thisValue = jsonObject.opt(keys.next());
    if (thisValue != null && thisValue.equals(value)) {
      return true;
    }
  }
  return false;
}

代码示例来源：origin: facebook/facebook-android-sdk

static Collection<Object> jsonObjectValues(JSONObject jsonObject) {
    ArrayList<Object> result = new ArrayList<Object>();

    @SuppressWarnings("unchecked")
    Iterator<String> keys = jsonObject.keys();
    while (keys.hasNext()) {
      result.add(jsonObject.opt(keys.next()));
    }

    return result;
  }
}

代码示例来源：origin: facebook/facebook-android-sdk

static Set<Map.Entry<String, Object>> jsonObjectEntrySet(JSONObject jsonObject) {
  HashSet<Map.Entry<String, Object>> result = new HashSet<Map.Entry<String, Object>>();
  @SuppressWarnings("unchecked")
  Iterator<String> keys = jsonObject.keys();
  while (keys.hasNext()) {
    String key = keys.next();
    Object value = jsonObject.opt(key);
    result.add(new JSONObjectEntry(key, value));
  }
  return result;
}

代码示例来源：origin: json-path/JsonPath

@Override
public Object getMapValue(Object obj, String key) {
  try {
    JSONObject jsonObject = toJsonObject(obj);
    Object o = jsonObject.opt(key);
    if (o == null) {
      return UNDEFINED;
    } else {
      return unwrap(o);
    }
  } catch (JSONException e) {
    throw new JsonPathException(e);
  }
}