Effective Java 2ed心得1

第二条

第一次试验

public class NuFacts {
	private final int a;
	private final int b;
	private final int c;
	private final int d;
	
	public static class Builder{
		private final int a;
		private final int b;
		private int c = 0;
		private int d = 0;
		public Builder(int a, int b) {
			this.a = a;
			this.b = b;
		}
		public Builder getC(int c) {
			this.c = c;
			return this;
		}
		public Builder getD(int d) {
			this.d = d;
			return this;
		}
		public NuFacts build() {
			return new NuFacts(this);
		}
	}
	private NuFacts(Builder builder) {
		a = builder.a;
		b = builder.b;
		c = builder.c;
		d = builder.d;
	}
}

public class Nu {
	private final int a = 0;
	public static void main(String args[]) {
		NuFacts nuFact1 = new NuFacts.Builder(100, 10).
			getC(1).getD(2).build();
		NuFacts nuFact2 = new NuFacts.Builder(100, 10).
			getC(1).build();
		
		
	}
}