java - 如果数组有效，如何创建传递的数组的深拷贝？

Question

因此，一个 IPv4 数组被传递给此方法，如果有效，则在实例变量“parts”中创建该数组的深拷贝

/**
 * If the ip address from the array passed (data) is valid,
 * makes a deep copy of the array passed in the instance variable parts.
 * For example, if data = {192,168,0,1}, parts should become {192,168,0,1}
 * by copying each item of data into corresponding item in parts.
 * If the ip address passed is invalid (for example {500,4,60,216}
 * or {192,16,01}, or {13,13,13,13,13}, parts should become {0,0,0,0}
 * 
 * remember to reset the instance array parts before you do anything else
 * @param data
 */
public void setParts(int[] data) {
this.parts = new int[4];
if (data.length != 4){
    parts = new int[]{0,0,0,0};
}
else
    for (int i = 0; i <= data.length; i++)
        if ((data[i] < 0) || (data[i] > 255))
            parts = new int[]{0,0,0,0};
        else
            parts[i] = data[i];
}

是我目前所拥有的。我可能会错过什么？

编辑:做了一个简单的改变:

for (int i = 0; i <= data.length; i++)

到

for (int i = 0; i < data.length; i++)

还有一个 JUnit 测试

    public void testSetPartsIntArray() {
    correct1.setParts(new int[]{12, 14, 16, 18});
    int[] a = correct1.getParts();
    assertEquals(4, a.length);
    assertEquals(12, a[0]);
    assertEquals(14, a[1]);
    assertEquals(16, a[2]);
    assertEquals(18, a[3]); 

    correct1.setParts(new int[]{-12, 14, 16, 18});
    a = correct1.getParts();
    assertEquals(4, a.length);
    assertEquals(0, a[0]);
    assertEquals(0, a[1]);
    assertEquals(0, a[2]);
    assertEquals(0, a[3]);  

工作直到

assertEquals(0, a[1]);

是什么导致它停在那里？

Answer 1

一旦发现无效值，就必须跳出循环:

for (int i = 0; i <= data.length; i++)
    if ((data[i] < 0) || (data[i] > 255)) {
        parts = new int[]{0,0,0,0};
        break;
    } else {
        parts[i] = data[i];
    }

在您失败的情况下，第一个元素 -12 无效，因此 parts 设置为 new int[]{0,0,0,0 }，但随后您继续循环，由于其余数字有效，您最终得到 {0, 14, 16, 18} 而不是 {0 , 0, 0, 0}。