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https://github.com/roroche/javaobjectsonsteroids
Example with useful libraries to speed up Java objects writing and testing.
https://github.com/roroche/javaobjectsonsteroids
assertj assertj-assertions autovalue equals hashcode pojo pojo-tester pojo-testing pojomatic tostring tostring-utilities
Last synced: 9 days ago
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Example with useful libraries to speed up Java objects writing and testing.
- Host: GitHub
- URL: https://github.com/roroche/javaobjectsonsteroids
- Owner: RoRoche
- License: apache-2.0
- Created: 2017-07-06T14:03:35.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2020-04-26T16:50:19.000Z (over 4 years ago)
- Last Synced: 2024-01-14T07:50:48.201Z (10 months ago)
- Topics: assertj, assertj-assertions, autovalue, equals, hashcode, pojo, pojo-tester, pojo-testing, pojomatic, tostring, tostring-utilities
- Language: Java
- Size: 407 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
Java objects on steroids
===
# 
###### by [Romain Rochegude](https://github.com/RoRoche)
---
# Introduction
* Many ways to see "objects": POJO, bean
* Many concepts: encapsulation, inheritance, polymorphism, immutability
* [Who Is an Object?](http://www.yegor256.com/2016/07/14/who-is-object.html)
* [Seven Virtues of a Good Object](http://www.yegor256.com/2014/11/20/seven-virtues-of-good-object.html)
---
# ==1.== Write simple immutable object
```java
public final class User {
private final int id;
private final String login;
private final String avatarUrl;
public User(
final int pId,
final String pLogin,
final String pAvatarUrl) {
id = pId;
login = pLogin;
avatarUrl = pAvatarUrl;
}
}
```
---
# ==2.== Improve pojo methods testing with [pojo-tester](http://www.pojo.pl/)
##
---
## Gradle installation:
```groovy
repositories {
jcenter()
}
dependencies {
testCompile 'pl.pojo:pojo-tester:${latest-version}'
}
```
---
## Write unit test:
```java
import pl.pojo.tester.api.assertion.Method;
import static pl.pojo.tester.api.assertion.Assertions.assertPojoMethodsFor;
public class UserTest {
@Test
public void Should_Pass_All_User_Tests() {
assertPojoMethodsFor(
User.class
).testing(
Method.EQUALS,
Method.HASH_CODE,
// Method.SETTER,
// Method.GETTER,
// Method.TO_STRING,
Method.CONSTRUCTOR
).areWellImplemented();
}
}
```
---
## Why...
* ...no getters/setters testing?
* Because [getters/setters are evil](http://www.yegor256.com/2014/09/16/getters-and-setters-are-evil.html)
* ...no `toString`?
* Because it expects a specific format that is not extensible
---
## The result is:
```java
Class fr.guddy.joos.domain.User has bad 'hashCode' method implementation.
The hashCode method should return same hash code for equal objects.
Current implementation returns different values.
Object:
fr.guddy.joos.domain.User@7946e1f4
and
fr.guddy.joos.domain.User@5cc7c2a6
have two different hash codes:
2034688500
and
1556595366
```
---
# ==3.== Improve pojo methods writing with [pojomatic](http://www.pojomatic.org/)
##
---
## Why pojomatic instead of Commons Lang, Guava or Lombok?
* Because pojomatic is only focused on the `equals(Object)`, `hashCode()` and `toString()` methods
* Because Commons Lang are verbose
* Because Guava has many other features
* Because Lombok needs an extra plugin and
---
## Gradle installation:
```java
compile 'org.pojomatic:pojomatic:2.0.1'
```
---
## Configure object:
```java
import org.pojomatic.Pojomatic;
import org.pojomatic.annotations.Property;
public final class User {
@Property
private final int id;
// ...
@Override
public boolean equals(final Object pObj) {
return Pojomatic.equals(this, pObj);
}
@Override
public int hashCode() {
return Pojomatic.hashCode(this);
}
}
```
---
# ==4.== Improve immutable writing with [auto-value](https://github.com/google/auto/tree/master/value)
##
---
## Gradle installation:
```groovy
compile 'com.google.auto.value:auto-value:1.2'
annotationProcessor 'com.google.auto.value:auto-value:1.2'
```
---
## Configure object:
```java
import com.google.auto.value.AutoValue;
@AutoValue
public abstract class Repo {
public abstract int id();
public abstract String name();
public abstract String description();
public abstract String url();
public static Repo create(
final int pId,
final String pName,
final String pDescription,
final String pUrl) {
return new AutoValue_Repo(pId, pName, pDescription, pUrl);
}
}
```
---
# ==5.== Improve object testing with [AssertJ Assertions Generator](http://joel-costigliola.github.io/assertj/assertj-assertions-generator.html)
##
---
## Why? Refer to [Single Statement Unit Tests](http://www.yegor256.com/2017/05/17/single-statement-unit-tests.html), for the following benefits:
* Reusability
* Brevity
* Readability
* Immutability
* Fluent test result
---
## Gradle installation:
### AssertJ dependency:
```
testCompile 'org.assertj:assertj-core:3.8.0'
```
### assertjGen plugin installation:
```groovy
buildscript {
repositories {
maven { url "https://plugins.gradle.org/m2/" }
}
dependencies {
classpath "gradle.plugin.com.github.opengl-8080:
assertjGen-gradle-plugin:1.1.3"
}
}
apply plugin: "com.github.opengl-BOBO.assertjGen"
```
---
### assertjGen plugin configuration:
```groovy
assertjGen {
classOrPackageNames = ['fr.guddy.joos.domain']
outputDir = 'src/test/java'
cleanOnlyFiles = true
assertjGenerator = 'org.assertj:assertj-assertions-generator:2.0.0'
}
```
---
## Run the `assertjGen` Gradle task to generate assertion classes
## Write unit test:
```java
import static fr.guddy.joos.domain.UserAssert.assertThat;
public class UserTest {
@Test
public void Should_Have_Matching_Id() {
assertThat(
new User(12,
"Romain",
"https://...")
).hasId(13);
}
}
```
---
## The result is:
```java
java.lang.AssertionError:
Expecting id of:
to be:
<13>
but was:
<12>
```
---
# Conclusion
* Focus on the objects
* Less boilerplate code
* On the way to DDD
* On the way to hexagonal architecture
*
---
# Bibliography
*
*
*
*
*
---
# Logo credits
Business graphic by freepik from Flaticon is licensed under CC BY 3.0. Made with Logo Maker