我正在尝试保存file.properties。我可以保存一个<String，String>映射。

但是，当我尝试保存<String，Integer>映射时，出现错误。

有没有办法保存<String，Integer>映射？

无效的代码：

    Map<String, Integer> int_map = new HashMap<String, Integer>();
    int_map.put("Red", 4);
    int_map.put("Orange-red", 3);
    int_map.put("Orange", 2);
    int_map.put("Green", 1);
    int_map.put("Blue", 0);

    Properties properties = new Properties(); // Crate properties object to store the data

    for (Map.Entry<String, Integer> entry : int_map.entrySet()) {
        properties.put(entry.getKey(), entry.getValue());
    }

    try {
        properties.store(new FileOutputStream(this.getFilesDir() + "data.properties"), null);
    } catch (IOException e) {
        e.printStackTrace();
    }

起作用的代码：

        Map<String, String> map = new HashMap<String, String>();

        map.put("hello", "world");
        
        Properties properties = new Properties(); // Crate properties object to store the data

        for (Map.Entry<String, String> entry : map.entrySet()) {
            properties.put(entry.getKey(), entry.getValue());
        }

        try {
            properties.store(new FileOutputStream(this.getFilesDir() + "data.properties"), null);
        } catch (IOException e) {
            e.printStackTrace();
        }

我尝试运行该错误时遇到的错误：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.trialanderror, PID: 24139
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.trialanderror/com.example.trialanderror.MainActivity}: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3555)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3707)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2220)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:237)
        at android.app.ActivityThread.main(ActivityThread.java:8016)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1087)
     Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
        at java.util.Properties.store0(Properties.java:836)
        at java.util.Properties.store(Properties.java:820)
        at com.example.trialanderror.MainActivity.onCreate(MainActivity.java:36)
        at android.app.Activity.performCreate(Activity.java:7957)
        at android.app.Activity.performCreate(Activity.java:7946)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3530)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3707) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2220) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:237) 
        at android.app.ActivityThread.main(ActivityThread.java:8016) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1087)