使用Jackson在JAVA中生成自定义JSON模式

我不熟悉这一点，并且在POJO/Bean中嵌套参数的用例中苦苦挣扎

要求-

使用Jackson为javabean/POJO类生成一个JSON模式（最新版本也可以），这样它就正确地包含了嵌套对象的结构，并且希望向嵌套的POJO添加自定义属性（在我的例子中，希望为每个嵌套的POJO参数添加一个完全分类的classname属性）

用例-

比如，我有一个Person类，如下所示。我用这个人作为我的一些操作的参数

public class Person {

    private String name;
    private String id;
    private int i;
    private Person2 p;
    private List<String> strList;
    private HashMap<String, String> strMap;
    private Person3[] p3;

    public void setName(String name){
        this.name = name;
    }

    public void setId(String id){
        this.id = id;
    }

    public void setI(int i){
        this.i = i;
    }

    public void setP(Person2 p){
        this.p = p;
    }

    public String getName(){
        return this.name;
    }

    public String getId(){
        return this.id;
    }

    public int getI(){
        return this.i;
    }

    public Person2 getP(){
        return this.p;
    }

    public void setStrList(List<String> strList){
        this.strList = strList;
    }

    public List<String> getStrList(){
        return this.strList;
    }

    public void setStrMap(HashMap<String, String> strMap){
        this.strMap = strMap;
    }

    public HashMap<String, String> getStrMap(){
        return this.strMap;
    }

    public void setP3(Person3[] p3){
        this.p3 = p3;
    }

    public Person3[] getP3(){
        return this.p3;
    }
}

Person类具有一些多值数据结构，如映射、数组，还可以具有嵌套的POJO。因此，我不想为这些类型的BEAN/POJO类生成一个JSON模式，还想为每个嵌套的POJO/BEAN放置一个的“classname”节点，具有一个完全分类的classname

为此，我经历了很多事情，但我无法用Jackson为这种情况找到一个简写

这里需要注意的是在嵌套的POJO属性模式中放入“classname”属性

---

这个问题肯定与此相关-

这可能是解决上述问题的方法之一，如下所示-

public static void main(String[] args) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        Class<?> cls = Person[].class;
        if(cls.isArray()){
            cls = cls.getComponentType();
        }
        String s = "{\"rootNode\":{\"classname\":\"" + cls.getName() + "\"},"
                + getAttributeClassnames(cls) + "}";
        s = s.replace("\",}", "\"}").replace("},}", "}}");
        System.out.println(s);
        s = mapper.generateJsonSchema(cls).getSchemaNode().put("type", "array")
                .put("classnames", s).toString();
        s = s.replace("\\", "").replace("\"{", "{").replace("}\"", "}");        
        System.out.println(s);
    }

static String getAttributeClassnames(Class<?> cls) {
    String s = "";      
        Field[] field = cls.getDeclaredFields();
        int i = 0;
        while (i < field.length) {              
            if (!(field[i].getType() == Boolean.class)
                    && !(field[i].getType() == Integer.class)
                    && !(field[i].getType() == Character.class)
                    && !(field[i].getType() == Byte.class)
                    && !(field[i].getType() == Short.class)
                    && !(field[i].getType() == Long.class)
                    && !(field[i].getType() == Float.class)
                    && !(field[i].getType() == Double.class)
                    && !(field[i].getType().isPrimitive())
                    && !(field[i].getType() == String.class)
                    && !(Collection.class.isAssignableFrom(field[i]
                            .getType()))
                    && !(Map.class.isAssignableFrom(field[i].getType()))
                    && !(Arrays.class.isAssignableFrom(field[i].getType()))) {
                if(field[i].getType() == cls){
                    if (i == field.length - 1) {
                        Class<?> name = null;
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                +"}";
                    } else {
                        Class<?> name = null;                       
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + "}" + ",";
                    }
                
                }else{
                    if (i == field.length - 1) {
                        Class<?> name = null;
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + getAttributeClassnames(name)
                                + "}";
                    } else {
                        Class<?> name = null;                       
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + getAttributeClassnames(name)
                                + "}" + ",";
                    }
                }
            }
            i++;
        }
    return s;
}

方法1 这是我将类名放入生成的模式中的代码。此代码处理提供数组或非数组参数时的情况。i、 e.可以成功处理Person.class和Person[]类。此代码无法处理Jackson上仍然存在的自引用问题-

下面的代码可以实例化如下-

public static void main(String[] args) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        Class<?> cls = Person[].class;
        if(cls.isArray()){
            cls = cls.getComponentType();
        }
        String s = "{\"rootNode\":{\"classname\":\"" + cls.getName() + "\"},"
                + getAttributeClassnames(cls) + "}";
        s = s.replace("\",}", "\"}").replace("},}", "}}");
        System.out.println(s);
        s = mapper.generateJsonSchema(cls).getSchemaNode().put("type", "array")
                .put("classnames", s).toString();
        s = s.replace("\\", "").replace("\"{", "{").replace("}\"", "}");        
        System.out.println(s);
    }

static String getAttributeClassnames(Class<?> cls) {
    String s = "";      
        Field[] field = cls.getDeclaredFields();
        int i = 0;
        while (i < field.length) {              
            if (!(field[i].getType() == Boolean.class)
                    && !(field[i].getType() == Integer.class)
                    && !(field[i].getType() == Character.class)
                    && !(field[i].getType() == Byte.class)
                    && !(field[i].getType() == Short.class)
                    && !(field[i].getType() == Long.class)
                    && !(field[i].getType() == Float.class)
                    && !(field[i].getType() == Double.class)
                    && !(field[i].getType().isPrimitive())
                    && !(field[i].getType() == String.class)
                    && !(Collection.class.isAssignableFrom(field[i]
                            .getType()))
                    && !(Map.class.isAssignableFrom(field[i].getType()))
                    && !(Arrays.class.isAssignableFrom(field[i].getType()))) {
                if(field[i].getType() == cls){
                    if (i == field.length - 1) {
                        Class<?> name = null;
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                +"}";
                    } else {
                        Class<?> name = null;                       
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + "}" + ",";
                    }
                
                }else{
                    if (i == field.length - 1) {
                        Class<?> name = null;
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + getAttributeClassnames(name)
                                + "}";
                    } else {
                        Class<?> name = null;                       
                        if(field[i].getType().isArray()){
                            name = field[i].getType().getComponentType();
                        }else{
                            name = field[i].getType();
                        }
                        s = s + "\"" + field[i].getName() + "\""
                                + ":{\"classname\":\""
                                + name.getName() + "\","
                                + getAttributeClassnames(name)
                                + "}" + ",";
                    }
                }
            }
            i++;
        }
    return s;
}

publicstaticvoidmain（字符串[]args）引发IOException{
ObjectMapper mapper=新的ObjectMapper（）；
类别cls=人[]。类别；
if（cls.isArray（））{
cls=cls.getComponentType（）；
}
字符串s=“{\'rootNode\”：{\'classname\：\”+cls.getName（）+“\”}
+getAttributeClassnames（cls）+“}”；
s=s.replace（“\”，“\”，“\”）。replace（“}，}，“}”）；
系统输出打印项次；
s=mapper.generateJsonSchema（cls.getSchemaOnode（）.put（“类型”、“数组”）
.put（“classnames”，s）.toString（）；
s=s.replace（“\\”，”）.replace（“\”{，“{”）.replace（“}\”，“}”）；
系统输出打印项次；
}
静态字符串getAttributeClassnames（类cls）{
字符串s=“”；
Field[]Field=cls.getDeclaredFields（）；
int i=0；
而（i"classnames":{
          "<attribute_name>":{
                                "classname":"<classname>"
                             }
}