博客

1 需求:

	将List<String>转化为List<Integer>, 
	1 按顺序排序
	2 获取List<Integer>中的最大值

2 代码实现:

import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.collections4.Transformer;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class TestUtils {

    public static void main(String[] args)  {
    
        List<String> functionIdStrList = new ArrayList<>();
        functionIdStrList.add("1");
        functionIdStrList.add("14");
        functionIdStrList.add("7");
        functionIdStrList.add("11");

        List<Integer> functionIdList = new ArrayList<>();
        CollectionUtils.collect(functionIdStrList, new Transformer() {
            @Override
            public Object transform(Object o) {
                return Integer.valueOf(o.toString());
            }

        }, functionIdList);

        Collections.sort(functionIdList);
        System.out.println(functionIdList);
        
   		Integer max = Collections.max(functionIdList);
        System.out.println("最大值 = " + max);
    }
}

结果如如下图: