java无法使用GSON（在Android上）将JSON对象转换为POJO

6 月，2 周 Questions & Answers 619

我在控制器中有以下方法：

public class FoundController {

private JSONObject accessPoint;
private JSONArray accessPoints;
private List<WlanNetwork> accessPointlist;
private Gson gson;

public FoundController() {
    this.accessPoint = new JSONObject();
    this.accessPoints = new JSONArray();
    this.accessPointlist = new ArrayList<>();
    this.gson = new Gson();
}


public List<WlanNetwork> getFoundWlanNetworks() {
    accessPoints = CommonHelper.getWifiList(Constants.Global.FILE_WPA_SUPLICANT_CONF);
    accessPointlist = new ArrayList<WlanNetwork>();

    for (int i = 0; i < accessPoints.length(); i++) {
        try {
            Logger.d(accessPoints.getJSONObject(i).toString());
            WlanNetwork accessPointPOJO = gson.fromJson(accessPoints.getJSONObject(i).toString(), WlanNetwork.class);
            Logger.d(accessPointPOJO.getSssid());
            accessPointlist.add(accessPointPOJO);
        } catch (Exception e) {
            Logger.e("Exception");
            Logger.e(e.getMessage());
        }
    }
    Logger.d(String.valueOf(accessPointlist.size()));
    return accessPointlist;
}

}

方法：

accessPoints.getJSONObject(i).toString()

 {"key_mgmt":"NONE","priority\"":"97","ssid":"test"}

但如果我尝试使用以下命令转换为POJO对象：

WlanNetwork accessPointPOJO = gson.fromJson(accessPoints.getJSONObject(i).toString(), WlanNetwork.class);

我总是会遇到以下例外情况：

No message/exception is set

模型类别如下所示：

public class WlanNetwork {
    private String sssid;
    private String key_mgmt;
    private String sim_slot;
    private String imsi;
    private String priority;

    public WlanNetwork(String sssid, String key_mgmt, String sim_slot, String imsi, String priority) {
        super();
        this.sssid = sssid;
        this.key_mgmt = key_mgmt;
        this.sim_slot = sim_slot;
        this.imsi = imsi;
        this.priority = priority;
    }

    public String getSssid() {
        return sssid;
    }

    public void setSssid(String sssid) {
        this.sssid = sssid;
    }

    public String getKey_mgmt() {
        return key_mgmt;
    }

    public void setKey_mgmt(String key_mgmt) {
        this.key_mgmt = key_mgmt;
    }

    public String getSim_slot() {
        return sim_slot;
    }

    public void setSim_slot(String sim_slot) {
        this.sim_slot = sim_slot;
    }

    public String getImsi() {
        return imsi;
    }

    public void setImsi(String imsi) {
        this.imsi = imsi;
    }

    public String getPriority() {
        return priority;
    }

    public void setPriority(String priority) {
        this.priority = priority;
    }
}

我几乎什么都试过了，但运气不好。请问有什么问题

非常感谢你的建议

编辑：

printStackTrace返回

java.lang.NullPointerException
10-16 12:54:56.421  11985-11985/com.testr W/System.err﹕ at com.orhanobut.logger.LoggerPrinter.log(LoggerPrinter.java:218)
10-16 12:54:56.421  11985-11985/com.testr W/System.err﹕ at com.orhanobut.logger.LoggerPrinter.d(LoggerPrinter.java:109)
10-16 12:54:56.421  11985-11985/com.testr W/System.err﹕ at com.orhanobut.logger.Logger.d(Logger.java:49)
10-16 12:54:56.421  11985-11985/com.testr W/System.err﹕ at com.testr.controller.FoundController.getFoundWlanNetworks(FoundController.java:38)
10-16 12:54:56.421  11985-11985/com.testr W/System.err﹕ at com.testr.view.fragment.Fragment_found.processWhatIsNeed(Fragment_found.java:51)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at com.testr.view.fragment.Fragment_found.onActivityCreated(Fragment_found.java:76)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.Fragment.performActivityCreated(Fragment.java:1970)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1051)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1207)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1572)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:493)
10-16 12:54:56.422  11985-11985/com.testr W/System.err﹕ at 安卓.os.Handler.handleCallback(Handler.java:808)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at 安卓.os.Handler.dispatchMessage(Handler.java:103)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at 安卓.os.Looper.loop(Looper.java:193)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at 安卓.app.ActivityThread.main(ActivityThread.java:5395)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:515)
10-16 12:54:56.423  11985-11985/com.testr W/System.err﹕ at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:837)
10-16 12:54:56.424  11985-11985/com.testr W/System.err﹕ at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:653)
10-16 12:54:56.424  11985-11985/com.testr W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)

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java无法使用GSON（在Android上）将JSON对象转换为POJO

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