Question

如何将字符串转换回对象？我有以下课程：

class Test {
    String name;
    String value;
    String testing;

    @Override
    public String toString() {
        return "Test{" +
                "name='" + name + '\'' +
                ", value='" + value + '\'' +
                ", testing='" + testing + '\'' +
                '}';
    }
}

class Testing {
   private List<Test> testing = new ArrayList<Test>();
   handling(testing.toString())
   public String handling(String testing) {
        // do some handling and return a string
   }
}

ArrayList testing必须通过转换为string来处理，例如，此后，我们得到以下字符串：

[Test{name='name1', value='value1', testing='testing1'}, Test{name='name2', value='value2', testing='testing2'}, Test{name='name3', value='value3', testing='testing3'}]

然后如何将字符串转换回Test的对象列表？

有人可以帮忙吗？

Answer 1

如果您不需要完全这种toString模式，而只需将您的Object转换为易于理解的格式，然后再转换回{{1} }，您可以像杰克逊Object这样无缝地 marshal 进行json并 parse 回到Object。有关快速入门，请参见https://www.baeldung.com/jackson-object-mapper-tutorial。

Answer 2

您可以创建其他构造函数，并使用以下字符串调用它们：

class Test {
    private String name;
    private String value;
    private String testing;

    Test(string objString) { 
        Pattern pattern = Pattern.compile("name=('.+'), value=('.+), testing=('.+')");
        Matcher matcher = pattern.matcher(objString);
        if (matcher.matches()) {
            name = matcher.group(1);
            value = matcher.group(2);
            testing = matcher.group(3);
        } else {
            throw new ArgumentException("Cannot parse""):
        }
    }

    @Override
    public String toString() {
        return "Test{" +
                "name='" + name + '\'' +
                ", value='" + value + '\'' +
                ", testing='" + testing + '\'' +
                '}';
    }
}

class Testing {

    doTesting(List<Test> testing) {
        List<String> testingAsString = new ArrayList<String>();

        // To string
        for (Test t : testing) {
            testingAsString.add(t.toString());
        }

        List<Test> clonedTesting = new ArrayList<Test>();
        // To Test
        for (String t : testingAsString) {
            clonedTesting.add(new Test(t));
        }

        // Here every test string is again an object of type Test
        for (Test t : clonedTesting) {
            System.out.println(t);
        }
    }  
}

如何在Java中将字符串转换回对象列表

2 个答案: