Java中比较两个SET是否相同
asuncool@gmail.com(yihaomen)发表于 2016-11-14 19:47:40
java api中，好像没有发现比较两个set 的内容是否一样的方法，只能自己写一个来实现了，其实也比较简单，比较记录数是否一样，然后看内容是否一致, 测试的方法如下:
程序代码
public static boolean equals(Set<?> set1, Set<?> set2){
if(set1 == null || set2 ==null){
return false;
}
if(set1.size()!=set2.size()){
return false;
}
return set1.containsAll(set2);
}
走单元测试:
程序代码
import org.junit.Test;
import java.util.HashSet;
import java.util.Set;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.is;
public class TestSetUtils {
@Test
public void test1() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("b");
test2.add("c");
assertThat(SetUtils.equals(test1, test2), is(false));
}
@Test
public void test2() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("a");
test2.add("b");
test2.add("c");
assertThat(SetUtils.equals(test1, test2), is(false));
}
@Test
public void test3() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
test1.add("c");
Set<String> test2 = new HashSet<>();
test2.add("a");
test2.add("b");
assertThat(SetUtils.equals(test1, test2), is(false));
}
//set ignore sequence
@Test
public void test4() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("b");
test2.add("a");
assertThat(SetUtils.equals(test1, test2), is(true));
}
@Test
public void test5() {
Set<String> test1 = new HashSet<>();
test1.add("a");
Set<String> test2 = new HashSet<>();
test2.add("a");
assertThat(SetUtils.equals(test1, test2), is(true));
}
}
程序代码public static boolean equals(Set<?> set1, Set<?> set2){
if(set1 == null || set2 ==null){
return false;
}
if(set1.size()!=set2.size()){
return false;
}
return set1.containsAll(set2);
}
走单元测试:
程序代码import org.junit.Test;
import java.util.HashSet;
import java.util.Set;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.is;
public class TestSetUtils {
@Test
public void test1() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("b");
test2.add("c");
assertThat(SetUtils.equals(test1, test2), is(false));
}
@Test
public void test2() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("a");
test2.add("b");
test2.add("c");
assertThat(SetUtils.equals(test1, test2), is(false));
}
@Test
public void test3() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
test1.add("c");
Set<String> test2 = new HashSet<>();
test2.add("a");
test2.add("b");
assertThat(SetUtils.equals(test1, test2), is(false));
}
//set ignore sequence
@Test
public void test4() {
Set<String> test1 = new HashSet<>();
test1.add("a");
test1.add("b");
Set<String> test2 = new HashSet<>();
test2.add("b");
test2.add("a");
assertThat(SetUtils.equals(test1, test2), is(true));
}
@Test
public void test5() {
Set<String> test1 = new HashSet<>();
test1.add("a");
Set<String> test2 = new HashSet<>();
test2.add("a");
assertThat(SetUtils.equals(test1, test2), is(true));
}
}