领域迁移android addRealmObjectField
我有以下课程领域迁移android addRealmObjectField,android,realm,Android,Realm,我有以下课程 public class Settings extends RealmObject { private String something; } 我想添加以下字段 public class AndroidBuild extends RealmObject { int one; int two; } 看来 public class Settings extends RealmObject { p
public class Settings extends RealmObject {
private String something;
}
我想添加以下字段
public class AndroidBuild extends RealmObject {
int one;
int two;
}
看来
public class Settings extends RealmObject {
private String something;
private AndroidBuild androidBuild;
}
if (oldVersion == 1) {
RealmObjectSchema settingsSchema = schema.get("Settings");
RealmObjectSchema androidBuildSchema = schema.get("AndroidBuild");
if (settingsSchema != null) {
settingsSchema.addRealmObjectField("androidBuild", androidBuildSchema);
oldVersion++;
}
}
所以,我的迁移看起来像
public class Settings extends RealmObject {
private String something;
private AndroidBuild androidBuild;
}
if (oldVersion == 1) {
RealmObjectSchema settingsSchema = schema.get("Settings");
RealmObjectSchema androidBuildSchema = schema.get("AndroidBuild");
if (settingsSchema != null) {
settingsSchema.addRealmObjectField("androidBuild", androidBuildSchema);
oldVersion++;
}
}
它崩溃了
07-11 15:05:06.384 9046-9046/com.cassby.terminal.cassby E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.cassby.terminal.cassby, PID: 9046
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cassby.terminal.cassby/com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String io.realm.RealmObjectSchema.getClassName()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String io.realm.RealmObjectSchema.getClassName()' on a null object reference
at io.realm.MutableRealmObjectSchema.addRealmObjectField(MutableRealmObjectSchema.java:126)
at com.cassby.terminal.cassby.Services.Database.RealmMigrations.migrate(RealmMigrations.java:36)
at io.realm.BaseRealm$6.onMigrationNeeded(BaseRealm.java:714)
at io.realm.internal.OsSharedRealm.runMigrationCallback(OsSharedRealm.java:520)
at io.realm.internal.OsSharedRealm.nativeGetSharedRealm(Native Method)
at io.realm.internal.OsSharedRealm.<init>(OsSharedRealm.java:184)
at io.realm.internal.OsSharedRealm.getInstance(OsSharedRealm.java:254)
at io.realm.BaseRealm.<init>(BaseRealm.java:124)
at io.realm.BaseRealm.<init>(BaseRealm.java:93)
at io.realm.Realm.<init>(Realm.java:153)
at io.realm.Realm.createInstance(Realm.java:424)
at io.realm.RealmCache.doCreateRealmOrGetFromCache(RealmCache.java:342)
at io.realm.RealmCache.createRealmOrGetFromCache(RealmCache.java:282)
at io.realm.Realm.getDefaultInstance(Realm.java:332)
at com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity.resolveStartingActivity(LaunchActivity.java:35)
at com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity.onCreate(LaunchActivity.java:29)
at android.app.Activity.performCreate(Activity.java:7009)
at android.app.Activity.performCreate(Activity.java:7000)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
07-11 15:05:06.384 9046-9046/com.cassby.terminal.cassby E/AndroidRuntime:FATAL EXCEPTION:main
进程:com.cassby.terminal.cassby,PID:9046
java.lang.RuntimeException:无法启动activity ComponentInfo{com.cassby.terminal.cassby/com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity}:java.lang.NullPointerException:尝试对空对象引用调用虚拟方法“java.lang.String io.realm.RealmObjectSchema.getClassName()”
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
位于android.app.ActivityThread.-wrap11(未知来源:0)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)上
位于android.os.Handler.dispatchMessage(Handler.java:106)
位于android.os.Looper.loop(Looper.java:164)
位于android.app.ActivityThread.main(ActivityThread.java:6494)
位于java.lang.reflect.Method.invoke(本机方法)
位于com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
原因:java.lang.NullPointerException:尝试对空对象引用调用虚拟方法“java.lang.String io.realm.RealmObjectSchema.getClassName()”
位于io.realm.MutableRealmObjectSchema.addRealmObjectField(MutableRealmObjectSchema.java:126)
在com.cassby.terminal.cassby.Services.Database.RealmMigrations.migrate(RealmMigrations.java:36)
在io.realm.BaseRealm$6.onMigrationRequired(BaseRealm.java:714)
位于io.realm.internal.OsSharedRealm.runMigrationCallback(OsSharedRealm.java:520)
位于io.realm.internal.OsSharedRealm.nativeGetSharedRealm(本机方法)
位于io.realm.internal.OsSharedRealm.(OsSharedRealm.java:184)
位于io.realm.internal.OsSharedRealm.getInstance(OsSharedRealm.java:254)
位于io.realm.BaseRealm.(BaseRealm.java:124)
位于io.realm.BaseRealm.(BaseRealm.java:93)
位于io.realm.realm.(realm.java:153)
位于io.realm.realm.createInstance(realm.java:424)
位于io.realm.RealmCache.doCreateRealmOrGetFromCache(RealmCache.java:342)
位于io.realm.RealmCache.createRealmOrGetFromCache(RealmCache.java:282)
位于io.realm.realm.getDefaultInstance(realm.java:332)
位于com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity.resolveStartingActivity(LaunchActivity.java:35)
位于com.cassby.terminal.cassby.UserStories.Launch.LaunchActivity.onCreate(LaunchActivity.java:29)
位于android.app.Activity.performCreate(Activity.java:7009)
位于android.app.Activity.performCreate(Activity.java:7000)
位于android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)上
位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
位于android.app.ActivityThread.-wrap11(未知来源:0)
在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)上
位于android.os.Handler.dispatchMessage(Handler.java:106)
位于android.os.Looper.loop(Looper.java:164)
位于android.app.ActivityThread.main(ActivityThread.java:6494)
位于java.lang.reflect.Method.invoke(本机方法)
位于com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
我做错了什么?您需要先添加表,所以
Realm.setDefaultConfiguration(new RealmConfiguration.Builder()
.name(DB_NAME)
.schemaVersion(SCHEMA_VERSION)
.migration((realm, oldVersion, newVersion) -> {
RealmSchema schema = realm.getSchema();
if (oldVersion == OLD_VERSION) {
schema.create("AndroidBuild")
.addField("one", int.class)
.addField("two", int.class);
schema.get("Settings")
.addRealmObjectField("androidBuild", schema.get("AndroidBuild"))
oldVersion++;
}
})
);
您需要首先添加表,所以
Realm.setDefaultConfiguration(new RealmConfiguration.Builder()
.name(DB_NAME)
.schemaVersion(SCHEMA_VERSION)
.migration((realm, oldVersion, newVersion) -> {
RealmSchema schema = realm.getSchema();
if (oldVersion == OLD_VERSION) {
schema.create("AndroidBuild")
.addField("one", int.class)
.addField("two", int.class);
schema.get("Settings")
.addRealmObjectField("androidBuild", schema.get("AndroidBuild"))
oldVersion++;
}
})
);
settingsSchema没有createMethod,addRealmObjectField希望schema对象不是类作为第二个目标。除了not之外,一切都很好。addField(“androidBuild”,androidBuild.class);'但是.addRealmObjectField(“androidBuild”,schema.get(“androidBuild”);'@AlexeyK修复了此设置schema没有方法createand addRealmObjectField期望schema对象不是类作为第二个目标一切都很好,除了不是“.addField”(“androidBuild”,androidBuild.class);”但是.addRealmObjectField(“androidBuild”,schema.get(“androidBuild”);'@亚历克谢克解决了这个问题