Byte.parseByte报错java.lang.NumberFormatException: unable to parse '向文件写东西' as integer

执行下面的语句报错

fileOutputStream.write(Byte.parseByte("向文件写东西"))

03-19 15:33:02.843 4963-4963/? E/AndroidRuntime: FATAL EXCEPTION: main
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{tech.androidstudio.filedemo/tech.androidstudio.filedemo.MainActivity}: java.lang.NumberFormatException: unable to parse '向文件写东西' as integer
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:3683)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:507)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:  Caused by: java.lang.NumberFormatException: unable to parse '向文件写东西' as integer
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.Integer.parse(Integer.java:383)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.Integer.parseInt(Integer.java:372)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.Integer.parseInt(Integer.java:332)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.Byte.parseByte(Byte.java:185)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at tech.androidstudio.filedemo.MainActivity.onCreate(MainActivity.java:45)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:3683) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:507) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
03-19 15:33:02.843 4963-4963/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 

03-19 15:33:02.913 61-154/? W/ActivityManager:   Force finishing activity tech.androidstudio.filedemo/.MainActivity

解决办法：

修改为：

String add = "向文件写东西";
fileOutputStream.write(add.getBytes());