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怎样在JAVA寫一個含未知類的參數的方法

private String getMainTitle(List<String> bs){
    for(String b:bs){
        if (b.equals("GOOD"){
            return "string";
        }
    }
    
    return null;
}

private String getMainTitle(String b){
    if (b.equals("GOOD"){
        return "string";
    }
    
    return null;
}

public String getTitleFromString(String b){
    return getMainTitle(b);
}

public String getTitleFromList(List<String> bs){    
    return getMainTitle(bs);
}

請問怎样在JAVA寫一個含未知類的參數的方法?

希望寫一個方法能替代getTitleFromString和getTitleFromList , 比如:

public String getTitleFromList(T<?> t){    
    return getMainTitle(t);
}

但我的語法有誤, 請問該怎样改寫?

高洛峰高洛峰2807 days ago601

reply all(4)I'll reply

  • 阿神

    阿神2017-04-18 10:53:05

    public String <T> getMainTitle(T obj){
        if(Map.class.isAssignableFrom(obj.getClass())){
            ((Map<?, ?>) data).forEach((k, v) -> {
                if (v.equals("GOOD")) {
                    return "string";
                }
              });            
        } else if(Vector.class.isAssignableFrom(obj.getClass())){
            for(String b:bs){
                if (b.equals("GOOD")) {
                    return "string";
                }
            }
        } else if ( b.equals("GOOD") ){
            return "string";
        }
        return null;
    }

    reply
    0
  • 阿神

    阿神2017-04-18 10:53:05

    
       private String getMainTitle(List<String> bs){
            for(String b:bs){
                if (b.equals("GOOD")) {
                    return "string";
                }
            }
    
            return null;
        }
    
        private String getMainTitle(String b){
            if (b.equals("GOOD")) {
                return "string";
            }
    
            return null;
        }
    
        public String getTitleFrom(String  b){
            return getMainTitle(b);
        }
    
        public String getTitleFrom(List<String> bs){
            return getMainTitle(bs);
        }

    reply
    0
  • ringa_lee

    ringa_lee2017-04-18 10:53:05

    This works

    private <T> T getMainTitle(T t){
        if (t.equals("GOOD")){
            return (T)"string";
        }
    
        return null;
    }
    
    public <T> T getTitleFromString(T t){
        return getMainTitle(t);
    }

    reply
    0
  • 怪我咯

    怪我咯2017-04-18 10:53:05

    // Object...objs相当一个Object[]数组,用来当做参数,表示有未知个参数传入,甚至可以不传参!
    public String getMainTitle(Object...objs) {
        for (Object obj : objs) {
             if(obj.toString().equals("GOOD")){
                 return "string";
             }
        }
        return null;
    }
    
    // 使用
    public void static main(String[] args) {
        getMainTitle();
        getMainTitle("sdfds", "Goods", "GOOD");
        getMainTitle(true, "GOOD");
        getMainTitle(111,1111);
    }

    reply
    0
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