java操作XML字符串简单、复杂字符串，对象接收，对象集合接收

Bertha 。 2022-12-30 13:36 236阅读 0赞

# java操作XML字符串 #

注意：用于接收xml解析后的对象，其属性名必须与对象节点名一致！

利用java反射及正则表达式匹配，与xml的高度无关。

## 1.操作简单xml字符串，获取对象。 ##

### 工具类 ###

/**
         * @Description: 解析xml字符串，用对象接收。要求接收的对象的属性名与xml的节点名一致
         * @Param: [obj 解析xml后封装到的对象, xmlStr xml字符串]
         * @return: java.lang.Object
         */
        public static Object parseXmlStrToObject(Object obj, String xmlStr) {
            //获取对象的所有属性
            Field[] fields = obj.getClass().getDeclaredFields();
            //遍历属性
            for (Field field : fields) {
                //设置属性障碍
                field.setAccessible(true);
                //得到属性名
                String fieldname = field.getName();
                try {
                    //用属性名匹配xml中的节点
                    Pattern p = Pattern.compile("<" + fieldname + ">.*?</" + fieldname + ">");
                    Matcher matcher = p.matcher(xmlStr);
                    while (matcher.find()) {
                        //匹配节点值
                        Matcher m1 = PATTERN.matcher(matcher.group(0).trim());
                        if (m1.find()) {
                            //拿到属性的值
                            String value = "".equals(m1.group(1).trim()) ? null : m1.group(1).trim();
                            //取属性类型
                            Class<?> beanType = field.getType();
                            //拼串，得到属性的setter方法名
                            String setMethodName = "set" + fieldname.substring(0, 1).toUpperCase() + fieldname.substring(1);
                            //得到属性的setter方法
                            Method m = obj.getClass().getMethod(setMethodName, beanType);
                            //调用setter方法
                            m.invoke(obj, value);
                        }
                    }
                } catch (Exception e) {
                    continue;
                }
            }
            return obj;
        }

### 测试类 ###

public static void main(String[] args) {
            String xml = "<root><username>测试用户名</username><password>测试密码</password></root>";
            Object obj = XMLUtil.parseXmlStrToObject(new TestDTO(), xml);
            System.out.println(obj);
        }

@Data
    public class TestDTO {
        private String username;
        private String password;
    }

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXFpYW5nOTE1_size_16_color_FFFFFF_t_70][]

## 2.操作较复杂xml，获取对象集合 ##

### 工具类 ###

/**
         * @Description: 解析xml字符串，返回对象集合
         * @Param: [obj, xmlStr]
         * @return: java.util.List<com.jdkj.detectSystem.Util.BaseObject>
         */
        @SneakyThrows
        public static List<BaseObject> parseXmlStrToObjectList(BaseObject obj, String xmlStr) {
            Field[] fields = obj.getClass().getDeclaredFields();
            List<Object> objs = new ArrayList<>();
            //临时变量，用于计算可匹配到的对象数目
            int count = 0;
            for (Field field : fields) {
                field.setAccessible(true);
                String fieldname = field.getName();
                Pattern p = Pattern.compile("<" + fieldname + ">.*?</" + fieldname + ">");
                Matcher matcher = p.matcher(xmlStr);
                while (matcher.find()) {
                    //对象的复制方法
                    Object _obj = obj.clone();
                    objs.add(_obj);
                    count++;
                }
                if (count > 0) {
                    //一旦获取到对象数组，结束循环
                    break;
                }
            }
            BaseObject[] objs2 = new BaseObject[count];
            for (int i = 0; i < count; i++) {
                Object obj1 = objs.get(i);
                for (Field field : fields) {
                    field.setAccessible(true);
                    String fieldname = field.getName();
                    try {
                        Pattern p = Pattern.compile("<" + fieldname + ">.*?</" + fieldname + ">");
                        Matcher matcher = p.matcher(xmlStr);
                        int num = 0;
                        while (matcher.find()) {
                            if (num == i) {
                                Matcher m1 = PATTERN.matcher(matcher.group(0).trim());
                                if (m1.find()) {
                                    String value = "".equals(m1.group(1).trim()) ? null : m1.group(1).trim();
                                    Class<?> beanType = field.getType();
                                    String setMethodName = "set" + fieldname.substring(0, 1).toUpperCase() + fieldname.substring(1);
                                    Method m = obj1.getClass().getMethod(setMethodName, beanType);
                                    m.invoke(obj1, value);
                                }
                            }
                            num++;
                        }
                    } catch (NullPointerException e) {
                        continue;
                    }
                }
                objs2[i] = (BaseObject) obj1;
            }
            return Arrays.asList(objs2);
        }

### 测试类 ###

public class Test01 {
    
        public static void main(String[] args) {
            String xml = "<root>" +
                            "<username>测试用户名1</username><password>测试密码1</password>" +
                            "<username>测试用户名2</username><password>测试密码2</password>" +
                            "<username>测试用户名3</username><password>测试密码3</password>" +
                         "</root>";
            List<BaseObject> list = XMLUtil.parseXmlStrToObjectList(new TestDTO(), xml);
            list.forEach(System.out::println);
        }
    }

@Data
    public class TestDTO extends BaseObject {
        private String username;
        private String password;
    }

public class BaseObject implements Cloneable {
        @Override
        public Object clone() {
            Object obj = null;
            try {
                obj = super.clone();
            } catch (CloneNotSupportedException e) {
                e.printStackTrace();
            }
            return obj;
        }
    }

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXFpYW5nOTE1_size_16_color_FFFFFF_t_70 1][]

## 3.复杂xml，获取对象及对象集合 ##

<root>
        <code>1</code>
        <user>
            <username>测试用户名1</username><password>测试密码1</password>
        </user>
        <user>
            <username>测试用户名2</username><password>测试密码2</password>
        </user>
        <user>
            <username>测试用户名3</username><password>测试密码3</password>
        </user>
    </root>"

//调用 2 介绍的较复杂xml，用此类接收，可得到xml中重复的user对象集合
    @Data
    public class TestDTO extends BaseObject {
        private String username;
        private String password;
    }

//调用 1 介绍的简单xml，用此类接收，可得到xml中非重复的code
    @Data
    public class TestDTO2 {
        private String code;
    }

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