Tag Archives: java

H2 Database: Missing UNIX_TIMESTAMP

So maybe you are running tests using an H2 database with your MySQL-based application, and you just got the message that the MySQL function UNIX_TIMESTAMP(value) is missing from the H2 database? No worries. With an H2 database, you can build your own UNIX_TIMESTAMP (or any other function you might need). I’m here going to show you one way to do it:

First, we need to create a class on the classpath of the application that connects to the H2 database, this is normally the application you are testing:

package h2;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class H2UserDefined {

    public static Long UNIX_TIMESTAMP(String d) throws ParseException {
        DateFormat dateFormat 
                          = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        Date dateresult = dateFormat.parse(d);
        return dateresult.getTime()/1000;
    }
}

Now we need to tell H2 that we have a new function to use. To do this we need some SQL to run against the H2 database:

CREATE ALIAS UNIX_TIMESTAMP FOR "h2.H2UserDefined.UNIX_TIMESTAMP";

Here we tell the H2 database that there is a new alias called UNIX_TIMESTAMP that can be used and that it is located in the package ‘h2’ with the path ‘H2UserDefines’ and a function name UNIX_TIMESTAMP. Quite simple 🙂

Tested on Play Framework 2.3.6, H2 v1.4

Spring Boot: Map JSON body with root node in @RequestBody

Say you have the following JSON:

{
  "rootNode": {
    "firstValue":"",
    "secondValue":""
  }
}

The class to use for this could look something like this:

public class MyValues {
  private String firstValue;
  private String secondValue;
  ...
}

This class will however not map directly to the JSON above via @RequestBody, and this is because the JSON contains a root node (“rootNode”)

The solution here is to wrap the MyValues class into a “root class” like this:

public class MyValuesWrapper {
  MyValues rootNode;
  ...
}

After this you should be able to parse the request body automatically with @ResponseBody like this:

 @PostMapping(value = "/myValues")
  public int postValues(@RequestBody MyValuesWrapper wrappedRequest) {
  
  // Optional: Unwrap for easier access
  MyValues request = wrappedRequest.getMyValues();
  ...

Hope this helps somebody (or me in the future 🙂 )

Tested on Spring Boot v2.3.8 and Java 11

Gradle: Integration/GUI test setup example with Spring and Protractor

Setting upp integration tests that depends on background process can be a challenge in Gradle. Here is one solution that I have used:

gradle.build

apply plugin: 'java'

/**
* Handle of the background process (script scope)
*/
Process backendProcess

/**
* Task to start the Spring server
*/
task beforeE2eTests {
  ProcessBuilder builder
  builder = new ProcessBuilder('./gradlew bootRun'.split(' '))
  builder.redirectErrorStream(true)

  doLast {
    println "Starting backend"
    backendProcess = builder.start()

    InputStream sto = backendProcess.getInputStream()
    BufferedReader redr = new BufferedReader(new InputStreamReader(sto))

    /**
    * To prevent Gradle to go to next task before the server has started 
    * we add a loop that finds a specific log line. When that 
    * line appears we are good to go to next task
    */
    def line
    while ((line = redr.readLine()) != null) {
      println line
      if (line.contains("Started WebApplication")) {
        println "Backend is ready"
        break;
      }
    }
  }

  finalizedBy 'afterE2eTests'
}

/**
* Task to stop the Spring server
*/
task afterE2eTests {
  doLast {
    println "Stopping backend"
    backendProcess.destroy()
  }

  mustRunAfter 'testAngularE2e'
}

/**
* Task to start E2E tests
*/
task testAngularE2e(type: Exec) {
  mustRunAfter 'beforeE2eTests'

  /**
  * Run the Protractor tests
  */
  commandLine 'node_modules/.bin/protractor', 'e2e/protractor.conf.js'
}

/**
* Main testing task
*/
testAll {
  dependsOn beforeE2eTests, testAngularE2e
}

Tested on OSX 10.15.0 and Gradle 4.10.2