May 2017 - Redino blog

Ext JS Image Reload

gbstack05/26/2017 0 Comments

In Ext JS, to reload or refresh an image, we can call updateSrc() method, and also setSrc() method is working as well.

var img = Ext.getCmp('img_a');
img.updateSrc('...'); // or img.setSrc('...');

1 2	var img = Ext.getCmp('img_a'); img.updateSrc('...'); // or img.setSrc('...');

And if the requested image is cached, we need use cache buster to avoid loading cached image.

Ext.create('Ext.Img', {
  src: 'http://redino.net/xxx.jpg?' + new Date().getTime()
});

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Ext.create('Ext.Img', {

src: 'http://redino.net/xxx.jpg?' + new Date().getTime()

});

Note that I found another post saying to use doComponentLayout method to refresh an image, but this method is deprecated since version 4.1.

Hibernate ConstraintViolationException

gbstack05/20/2017 0 Comments

In following code (a JUnit test method) I'm trying to delete specified users from database

    @Test
    @Transactional
    public void testAddPermissions(){
        Session session = sysUserDao.getSessionFactory().openSession();
        List<SysUser> list = (List<SysUser>)session.createQuery("from SysUser where userName='adfadsfm'").list();
        if(list != null && list.size() > 0){
            session.delete(list.get(0));
            session.flush();
        }

        ...
    }

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@Test

@Transactional

public void testAddPermissions(){

Session session = sysUserDao.getSessionFactory().openSession();

List<SysUser> list = (List<SysUser>)session.createQuery("from SysUser where userName='adfadsfm'").list();

if(list != null && list.size() > 0){

session.delete(list.get(0));

session.flush();

}

...

}

But when running above code, I got following exception:

org.hibernate.exception.ConstraintViolationException: could not execute batch

at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:129)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:126)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.performExecution(BatchingBatch.java:132)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.doExecuteBatch(BatchingBatch.java:111)
at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.execute(AbstractBatchImpl.java:163)
at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.executeBatch(JdbcCoordinatorImpl.java:226)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:484)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:351)
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:350)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:56)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1222)
at com.dfweb.service.impl.SysUserServiceImplTest.testAddPermissions(SysUserServiceImplTest.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.sql.BatchUpdateException: Cannot delete or update a parent row: a foreign key constraint fails (db_df.permission_sys_user, CONSTRAINT FK_2l5pbq5juqkbrg6rtqes6w1el FOREIGN KEY (users_id) REFERENCES sys_user (id))
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2055)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1467)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:1135)
at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.performExecution(BatchingBatch.java:123)
... 41 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails (db_df.permission_sys_user, CONSTRAINT FK_2l5pbq5juqkbrg6rtqes6w1el FOREIGN KEY (users_id) REFERENCES sys_user (id))
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1041)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4237)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4169)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2617)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2825)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2156)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2441)
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2007)
... 44 more

Reason

This is because there is an RESTRICT reference for foreign key of permission_sys_user that references id column of sys_user table.

So deleting the SysUser entity and keep its related permissions in permission_sys_user table will break the foreign key constraint of permission_sys_user table (references sys_user table with default RESTRICT reference option).

Solution

Following is SysUser class related source code

@ManyToMany(cascade = { CascadeType.PERSIST,
      CascadeType.MERGE }, mappedBy = "users", targetEntity = Permission.class)
private Set<Permission> permissions;

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@ManyToMany(cascade = { CascadeType.PERSIST,

CascadeType.MERGE }, mappedBy = "users", targetEntity = Permission.class)

private Set<Permission> permissions;

One possible solution is to remove its related records in permission_sys_user table when deleting SysUser entity, so change SysUser to following will fix this issue:

@ManyToMany(cascade = { CascadeType.PERSIST,
      CascadeType.MERGE, CascadeType.REMOVE }, mappedBy = "users", targetEntity = Permission.class)
private Set<Permission> permissions;

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@ManyToMany(cascade = { CascadeType.PERSIST,

CascadeType.MERGE, CascadeType.REMOVE }, mappedBy = "users", targetEntity = Permission.class)

private Set<Permission> permissions;

Above code adds CascadeType.REMOVE for ManyToMany annotation's cascade attribute. This will make deleting SysUser entity will trigger deleting related Permission entities.

CakePHP Get Version

gbstack05/09/2017 0 Comments

To find out current version of CakePHP, we can use following methods:

CakePHP 2.x

Open lib/Cake/VERSION.txt file, the version number is at bottom of file.

CakePHP 3.x

Open vendor/cakephp/cakephp/VERSION.txt file, the version number is at bottom of file.

And if you want to get version in code, we can use following code

Configure::version()

1	Configure::version()

Under the Hood

The Configure class is defined at lib/Cake/Core/Configuration.php file, reading the code we will find it's actually reading the VERSION.txt file (the file we mentioned above) to find out current version as well.