Java Gson 抛出 MalformedJsonException 和其他异常

Gson throws MalformedJsonException, and other Exceptions

提问by bijiDango

I tried to save data to json string in a txt file using Gson and then restore it using Gson either. Things go well if I do it in eclipse. But when packaged to jar, Gson throws Exceptions.

我尝试使用 Gson 将数据保存到 txt 文件中的 json 字符串，然后使用 Gson 恢复它。如果我在 eclipse 中做这件事，事情会很顺利。但是当打包到 jar 时，Gson 会抛出异常。

Here is the code for saving the file.

这是保存文件的代码。

String gsonStr = gson.toJson(masterShips);  // masterShips is ArrayList<Ship>
BufferedWriter writer = null;
try {
    writer = new BufferedWriter(new FileWriter("D:\master_ship.txt"));
    writer.write(gsonStr);
} catch (IOException e) {
    System.err.println(e);
} finally {
    if (writer != null) {
        try {
            writer.close();
        } catch (IOException e) {
            System.err.println(e);
        }
    }
}

Then I read the file in eclipse using this code (and it works):

然后我使用此代码在 eclipse 中读取文件（并且它有效）：

Scanner in = new Scanner(new FileReader("D:\master_ship.txt"));

String str = in.nextLine();
Log.toDebug(str);
in.close();
JsonParser parser = new JsonParser();
JsonElement je = parser.parse(str);
JsonArray ja = je.getAsJsonArray();
for (int i=0; i<ja.size(); ++i) { 
    ... 
}

But after packaged into jar and run in cmd, Exception occurs:

但是打包成jar后在cmd中运行，出现异常：

Exception in thread "main" com.google.gson.JsonSyntaxException: com.google.gson.
stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malform
ed JSON at line 1 column 4
        at com.google.gson.JsonParser.parse(JsonParser.java:65)
        at com.google.gson.JsonParser.parse(JsonParser.java:45)
        at kan.util.Master.loadMasterShip(Master.java:44)
        at kan.util.Master.load(Master.java:27)
        at kan.Main.main(Main.java:22)
Caused by: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLeni
ent(true) to accept malformed JSON at line 1 column 4
        at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1505)
        at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1386)
        at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:531)
        at com.google.gson.stream.JsonReader.peek(JsonReader.java:414)
        at com.google.gson.JsonParser.parse(JsonParser.java:60)
        ... 4 more

According to the hint of the Exception, I changed my code and it still works in eclipse:

根据异常的提示，我更改了我的代码，它在 eclipse 中仍然有效：

Scanner in = new Scanner(new FileReader("D:\master_ship.txt"));

String str = in.nextLine();
in.close();

Reader reader = new StringReader(str);
JsonReader jr = new JsonReader(reader);
jr.setLenient(true);
JsonParser parser = new JsonParser();
JsonElement je = parser.parse(jr);
JsonArray ja = je.getAsJsonArray();
for (int i=0; i<ja.size(); ++i) { 
... 
}

But jar failed and throws

但是 jar 失败并抛出

Exception in thread "main" java.lang.IllegalStateException: This is not a JSON A
rray.
    at com.google.gson.JsonElement.getAsJsonArray(JsonElement.java:106)
    at kan.util.Master.loadMasterShip(Master.java:58)
    at kan.util.Master.load(Master.java:30)
    at kan.Main.main(Main.java:22)

As suggested by Sotirios I cut the length of the arraylist down, and when I increase the number of ships to 4, things go wrong. Here is the json:

正如 Sotirios 所建议的，我减少了数组列表的长度，当我将船的数量增加到 4 时，事情就出错了。这是json：

[{"id":1,"name":"睦月","type":2,"rank":2,"fuelMax":15,"bulletMax":15,"slotNum":2,"speed":10,"afterLv":20,"afterId":254,"range":1,"powerups":[1,1,0,0]},{"id":2,"name":"如月","type":2,"rank":1,"fuelMax":15,"bulletMax":15,"slotNum":2,"speed":10,"afterLv":20,"afterId":255,"range":1,"powerups":[0,1,0,0]},{"id":6,"name":"長月","type":2,"rank":1,"fuelMax":15,"bulletMax":15,"slotNum":2,"speed":10,"afterLv":20,"afterId":258,"range":1,"powerups":[0,1,0,0]},{"id":7,"name":"三日月","type":2,"rank":1,"fuelMax":15,"bulletMax":15,"slotNum":2,"speed":10,"afterLv":20,"afterId":260,"range":1,"powerups":[0,1,0,0]}]
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             ↑ colunm 473

Exception in thread "main" com.google.gson.JsonSyntaxException: com.google.gson.
stream.MalformedJsonException: Unterminated object at line 1 column 473
        at com.google.gson.internal.Streams.parse(Streams.java:56)
        at com.google.gson.JsonParser.parse(JsonParser.java:84)
        at kan.util.Master.loadMasterShip(Master.java:55)
        at kan.util.Master.load(Master.java:30)
        at kan.Main.main(Main.java:22)
Caused by: com.google.gson.stream.MalformedJsonException: Unterminated object at
 line 1 column 473
        at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1505)
        at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:480)
        at com.google.gson.stream.JsonReader.hasNext(JsonReader.java:403)
        at com.google.gson.internal.bind.TypeAdapters.read(TypeAdapters.java:
666)
        at com.google.gson.internal.bind.TypeAdapters.read(TypeAdapters.java:
659)
        at com.google.gson.internal.bind.TypeAdapters.read(TypeAdapters.java:
642)
        at com.google.gson.internal.Streams.parse(Streams.java:44)
        ... 4 more

Can anyone help me with this, you will be reaally preciated!

任何人都可以帮我解决这个问题，你会很感激的！

回答by Tulsiram Rathod

Use this class

使用这个类

import java.util.List;

public class GsonResponse
{
    public int id;
    public String name;
    public int type;
    public int rank;
    public int fuelMax;
    public int bulletMax;
    public int slotNum;
    public int speed;
    public int afterLv;
    public int afterId;
    public int range;
    public List<Integer> powerups;
    /**
     * @return the id
     */
    public int getId() {
        return id;
    }
    /**
     * @param id the id to set
     */
    public void setId(int id) {
        this.id = id;
    }
    /**
     * @return the name
     */
    public String getName() {
        return name;
    }
    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }
    /**
     * @return the type
     */
    public int getType() {
        return type;
    }
    /**
     * @param type the type to set
     */
    public void setType(int type) {
        this.type = type;
    }
    /**
     * @return the rank
     */
    public int getRank() {
        return rank;
    }
    /**
     * @param rank the rank to set
     */
    public void setRank(int rank) {
        this.rank = rank;
    }
    /**
     * @return the fuelMax
     */
    public int getFuelMax() {
        return fuelMax;
    }
    /**
     * @param fuelMax the fuelMax to set
     */
    public void setFuelMax(int fuelMax) {
        this.fuelMax = fuelMax;
    }
    /**
     * @return the bulletMax
     */
    public int getBulletMax() {
        return bulletMax;
    }
    /**
     * @param bulletMax the bulletMax to set
     */
    public void setBulletMax(int bulletMax) {
        this.bulletMax = bulletMax;
    }
    /**
     * @return the slotNum
     */
    public int getSlotNum() {
        return slotNum;
    }
    /**
     * @param slotNum the slotNum to set
     */
    public void setSlotNum(int slotNum) {
        this.slotNum = slotNum;
    }
    /**
     * @return the speed
     */
    public int getSpeed() {
        return speed;
    }
    /**
     * @param speed the speed to set
     */
    public void setSpeed(int speed) {
        this.speed = speed;
    }
    /**
     * @return the afterLv
     */
    public int getAfterLv() {
        return afterLv;
    }
    /**
     * @param afterLv the afterLv to set
     */
    public void setAfterLv(int afterLv) {
        this.afterLv = afterLv;
    }
    /**
     * @return the afterId
     */
    public int getAfterId() {
        return afterId;
    }
    /**
     * @param afterId the afterId to set
     */
    public void setAfterId(int afterId) {
        this.afterId = afterId;
    }
    /**
     * @return the range
     */
    public int getRange() {
        return range;
    }
    /**
     * @param range the range to set
     */
    public void setRange(int range) {
        this.range = range;
    }
    /**
     * @return the powerups
     */
    public List<Integer> getPowerups() {
        return powerups;
    }
    /**
     * @param powerups the powerups to set
     */
    public void setPowerups(List<Integer> powerups) {
        this.powerups = powerups;
    }    
}

just add below code where u parse

只需在你解析的地方添加下面的代码

String strJson = "[{\"id\":1,\"name\":\"睦月\",\"type\":2,\"rank\":2,\"fuelMax\":15,\"bulletMax\":15,\"slotNum\":2,\"speed\":10,\"afterLv\":20,\"afterId\":254,\"range\":1,\"powerups\":[1,1,0,0]},{\"id\":2,\"name\":\"如月\",\"type\":2,\"rank\":1,\"fuelMax\":15,\"bulletMax\":15,\"slotNum\":2,\"speed\":10,\"afterLv\":20,\"afterId\":255,\"range\":1,\"powerups\":[0,1,0,0]},{\"id\":6,\"name\":\"長月\",\"type\":2,\"rank\":1,\"fuelMax\":15,\"bulletMax\":15,\"slotNum\":2,\"speed\":10,\"afterLv\":20,\"afterId\":258,\"range\":1,\"powerups\":[0,1,0,0]},{\"id\":7,\"name\":\"三日月\",\"type\":2,\"rank\":1,\"fuelMax\":15,\"bulletMax\":15,\"slotNum\":2,\"speed\":10,\"afterLv\":20,\"afterId\":260,\"range\":1,\"powerups\":[0,1,0,0]}]";
        GsonResponse gsonResponse = null;
        try {
            gsonResponse = new Gson().fromJson(strJson,
                    GsonResponse.class);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }