总结:

它被称为“流畅接口”或“方法链接”。 这不是“标准”Java，尽管你现在看到的越来越多(在jQuery中工作得很好) 它违反了JavaBean规范，因此它将与各种工具和库分开，特别是JSP构建器和Spring。 它可能会阻止JVM通常会做的一些优化 一些人认为它能清理代码，另一些人认为它“可怕”

还有一些没有提到的要点:

This violates the principal that each function should do one (and only one) thing. You may or may not believe in this, but in Java I believe it works well. IDEs aren't going to generate these for you (by default). I finally, here's a real-world data point. I have had problems using a library built like this. Hibernate's query builder is an example of this in an existing library. Since Query's set* methods are returning queries, it's impossible to tell just by looking at the signature how to use it. For example: Query setWhatever(String what); It introduces an ambiguity: does the method modify the current object (your pattern) or, perhaps Query is really immutable (a very popular and valuable pattern), and the method is returning a new one. It just makes the library harder to use, and many programmers don't exploit this feature. If setters were setters, it would be clearer how to use it.

因为它不返回void，所以它不再是一个有效的JavaBean属性setter。如果您是世界上使用可视化“Bean Builder”工具的7个人之一，或者是使用JSP-bean-setProperty元素的17个人之一，那么这可能很重要。

如果你不想从setter返回'this'，但又不想使用第二个选项，你可以使用下面的语法来设置属性:

list.add(new Employee()
{{
    setName("Jack Sparrow");
    setId(1);
    setFoo("bacon!");
}});

顺便说一句，我认为它在c#中略干净:

list.Add(new Employee() {
    Name = "Jack Sparrow",
    Id = 1,
    Foo = "bacon!"
});

这一点也不坏。但是它与JavaBeans Spec不兼容。

有很多规范依赖于这些标准访问器。

你总能让它们共存。

public class Some {
    public String getValue() { // JavaBeans
        return value;
    }
    public void setValue(final String value) { // JavaBeans
        this.value = value;
    }
    public String value() { // simple
        return getValue();
    }
    public Some value(final String value) { // fluent/chaining
        setValue(value);
        return this;
    }
    private String value;
}

现在我们可以一起用了。

new Some().value("some").getValue();

下面是另一个版本的不可变对象。

public class Some {

    public static class Builder {

        public Some build() { return new Some(value); }

        public Builder value(final String value) {
            this.value = value;
            return this;
        }

        private String value;
    }

    private Some(final String value) {
        super();
        this.value = value;
    }

    public String getValue() { return value; }

    public String value() { return getValue();}

    private final String value;
}

现在我们可以这么做了。

new Some.Builder().value("value").build().getValue();

坏习惯: setter集 getter get

如果显式地声明一个方法，为U

setPropertyFromParams(array $hashParamList) { ... }

如果在整个应用程序中使用相同的约定，则似乎没有问题。

另一方面，如果应用程序的现有部分使用标准约定，我会坚持下去，并向更复杂的类添加构建器

public class NutritionalFacts {
    private final int sodium;
    private final int fat;
    private final int carbo;

    public int getSodium(){
        return sodium;
    }

    public int getfat(){
        return fat;
    }

    public int getCarbo(){
        return carbo;
    }

    public static class Builder {
        private int sodium;
        private int fat;
        private int carbo;

        public Builder sodium(int s) {
            this.sodium = s;
            return this;
        }

        public Builder fat(int f) {
            this.fat = f;
            return this;
        }

        public Builder carbo(int c) {
            this.carbo = c;
            return this;
        }

        public NutritionalFacts build() {
            return new NutritionalFacts(this);
        }
    }

    private NutritionalFacts(Builder b) {
        this.sodium = b.sodium;
        this.fat = b.fat;
        this.carbo = b.carbo;
    }
}