List<MyTest> myTestList =new ArrayList<>(); myTestList.add(new MyTest("1","2","3")); myTestList.add(new MyTest("2","3","1")); myTestList.add(new MyTest("3","2","1")); 使用java实现，求对象跟对象比同一个属性，最大值-0.5

可以使用双重循环来比较每个对象之间的同一个属性的差值，计算最大值并减去0.5。代码如下：

double maxDiff = Double.MIN_VALUE;

for (int i = 0; i < myTestList.size() - 1; i++) {
    MyTest obj1 = myTestList.get(i);
    for (int j = i + 1; j < myTestList.size(); j++) {
        MyTest obj2 = myTestList.get(j);
        double diff = Math.abs(Double.parseDouble(obj1.getProperty()) - Double.parseDouble(obj2.getProperty()));
        if (diff > maxDiff) {
            maxDiff = diff;
        }
    }
}

maxDiff -= 0.5;
System.out.println("最大差值为：" + maxDiff);

其中，`MyTest`类是一个自定义的类，包含三个属性：`property1`、`property2`和`property3`。为了简化代码，这里只取了一个属性作为比较差值的依据。你需要将`getProperty()`方法替换成你要比较的属性的getter方法。