Generate setters that return self in Eclipse

问题

I'd like to have my setters so that I can chain them like:

myPojo.setX(x).setY(y);

Usually I generate setters with Eclipse but unfortunately code template for setters allows me to change only the body of the setter, not the signature.

What would be the easiest way to complete the above? Besides search-and-replace + manual editing? :)

回答1:

You could use the Editor/Templates for this purpose. To define a new Template open the Preferences Window, then Java->Editor->Templates. In this window you can define a new template and give it a name. For example:

public ${enclosing_type} setName(${argType} name) {
    this.name = name;
    return this;
}

Give it a name, e.g. settr. You can then use this template in your java code by typing 'settr' and then Ctrl-Space.

回答2:

I can offer a kind of patch that however does not require any additional installations.

Go to Window/preferences/Java/Code Style/Code templates. Edit "setter body" template as following:

${field} = ${param};
return this;

Now when you run "generate getters and setters" it will create setter like:

public void setMyField(String myField) {
    this.myField = myField;
    return this;
}

This obviously cause compilation error because the method type is void. But you can strike Ctrl-F and replace all 'public void set' by public YourClassName set.

It is a patch, but it works...

回答3:

You might be able to use the fluent-builders-generator plugin to generate setters in the way you want to.

回答4:

Notepad++ solution:

Data:

JavaType variableName;

Search regex:

(.*) (.*);

Replace regex

public JavaType with\2\(\1 p\2\) { this.\2 = p\2; return this; }

You have to manually correct method name, since it does not uppercase the first letter of variable name.

回答5:

I use withField naming pattern with this template

public ${enclosing_type} with${Field}(${argType} ${param}) {
    set${Field}(${param});
    return this;
}

I think it was inspired by @paweloque's answer at the time. The only differences are the added {$Field} and ${param} which are used to name the method and arguments and call the real setter generated by eclipse in the method body.

What's great about templates is that you can create your with methods using the autocomplete plus a few tabs while filing up the template's variables.

The result is something like this :

public Foo withBar(String bar)
{
    setBar(bar);
    return this;
}

Here is a screenshot to set this up in eclipse:

回答6:

My two cent on this, I (miss)use the

Preferences > Java > Code Style > Code Templates > Comments > Setter

and put there the following template:

/**
 * @param ${param} the ${bare_field_name} to set
 */
// public ${enclosing_type} ${bare_field_name}(${field_type} ${param}) {
//     ${enclosing_method}(${param});
//  return this;
// }

Benefit:

It can be used when generating getters setters using
```
Source > Generate Getters and Setters...
```
It can be used when generating a single setter while typing in the editor set<start-of-fieldname> and hitting Ctrl+Space.

Drawbacks:

You have to tick generate comments when generating getters setters.
You have to remove the line comment starters, Ctrl+F // and replace with empty string.

Unfortunately, I could not find a way to uppercase the first letter of the field name which would have made using a prefix such as with possible.

回答7:

One alternative would be to use Lombok's @Setter and @Getter. Lombok enhances your classes at compiled based on some annotations. It works well on the command line and it has Eclipse support.

@Getter @Setter
public class Point {
    int x, y;

    static void test() {
        new Point().setX(1).setY(2);
    }
}

And in lombok.config :

lombok.accessors.chain=true

回答8:

With JavaForger you could use the template as given below to generate the setters. It does mean that you'll have to run a main method for every class that you want generate getters and setters for.

<#list fields as field>
  /**
   * Sets the ${field.name} of the {@link ${class.name}}.
   *
   * @param ${field.name} The input {@link ${field.nonPrimitiveType}}. 
   */
  public ${class.name} ${field.setter}(${field.type} ${field.name}) {
    this.${field.name} = ${field.name};
    return this;
  }
</#list>

The code below executes the template above (setters.javat) for a class called "myClass.java" and merges the generated code with the inputclass. It will override existing setters if they exist.

JavaForgerConfiguration config = JavaForgerConfiguration.builder()
  .withTemplate("setters.javat")
  .withMergeClassProvider(ClassProvider.fromInputClass(s -> s))
  .withOverride(true)
  .build();
JavaForger.execute(config, "myClass.java");

You will have to add the location of "setters.javat" with:

StaticJavaForgerConfiguration.addTemplateLocation("my/location/");

The project can be found here: https://github.com/daanvdh/JavaForger.

来源：https://stackoverflow.com/questions/12294627/generate-setters-that-return-self-in-eclipse

标签

java

eclipse

code-generation

pojo