从JAVA代码生成Schema：https://github.com/victools/jsonschema-generator

引入依赖

        <dependency>
            <groupId>com.github.victools</groupId>
            <artifactId>jsonschema-generator</artifactId>
            <version>4.28.0</version>
        </dependency>

代码开发

pojo 生成schema 工具类

import com.fasterxml.jackson.databind.JsonNode;
import com.github.victools.jsonschema.generator.OptionPreset;
import com.github.victools.jsonschema.generator.SchemaGenerator;
import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
import com.github.victools.jsonschema.generator.SchemaVersion;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileReader;
import java.io.LineNumberReader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.UUID;

@Slf4j
public class GenerateSchema {
    public static Class<?> getClass(String dirs, String rootClassName) {
        CustomClassLoader myClassLoader = (CustomClassLoader) AccessController.doPrivileged((PrivilegedAction) () -> new CustomClassLoader(dirs));
        return myClassLoader.findClass(rootClassName);
    }

    public static JsonNode getSchema(Class<?> type) {
        SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
        SchemaGeneratorConfig config = configBuilder.build();
        SchemaGenerator generator = new SchemaGenerator(config);
        try {
            return generator.generateSchema(type);
        } catch (Exception exception) {
            log.error("generate jsonSchema fail: ", exception);
        }
        return null;
    }

    public static JsonNode pojo2Schema(MultipartFile[] files, String rootClass) {
        String fileSeparator = File.separator;
        String dirs = System.getProperty("user.dir") + fileSeparator + "upload" + fileSeparator + UUID.randomUUID() + fileSeparator;
        File dir = new File(dirs);
        if (!dir.exists()) {
            boolean mkdirs = dir.mkdirs();
            log.info("mkdirs result：" + mkdirs);
        }
        try {
            String rootClassName = null;
            for (MultipartFile file : files) {
                String originalFilename = file.getOriginalFilename();
                String path = dirs + originalFilename;
                File newFile = FileUtils.getFile(path);
                if (!newFile.getParentFile().exists()) {
                    boolean mkdirs = newFile.getParentFile().mkdirs();
                    log.info("mkdirs result:" + mkdirs);
                }
                // 保存文件
                file.transferTo(newFile);
                // 这里重写类路径
                if (!getClassPath(newFile)) {
                    return null;
                }
                // 编译成class
                Tools.javac(path);
                // 将生成的class文件移动到对应包名的路径下 com.fawkes.PreCheck 则是 com/fawkes
                String classPath = path.replace(".java", ".class");
                String className = "org.test.entity";
                if (StringUtils.isNotBlank(originalFilename) && originalFilename.startsWith(rootClass)) {
                    rootClassName = className + "." + rootClass;
                }
                String replace = dirs + className.replace(".", fileSeparator);
                File file2 = new File(replace);
                if (!file2.exists()) {
                    boolean mkdirs = file2.mkdirs();
                    log.info("mkdirs result：" + mkdirs);
                }
                String name = replace + fileSeparator + originalFilename;
                String replace1 = name.replace(".java", ".class");
                File file1 = new File(replace1);
                if (!file1.exists()) {
                    boolean createRes = file1.createNewFile();
                    log.info("createRes :" + createRes);
                }
                FileCopyUtils.copy(new File(classPath), file1);
            }
            // 获取类
            Class<?> clazz = getClass(dirs, rootClassName);
            return getSchema(clazz);
        } catch (Exception exception) {
            log.info("java2Schema error ", exception);
        } finally {
            // 删除生成的文件和文件夹
            forceDelete(dir);
        }
        return null;
    }

    /**
     * 读取文件 package 那一行
     */
    public static boolean getClassPath(File file) {
        try (FileReader in = new FileReader(file); LineNumberReader reader = new LineNumberReader(in)) {
            reader.setLineNumber(1);
            String s;
            while ((s = reader.readLine()) != null) {
                if (s.startsWith("package")) {
                    return s.equals("package org.test.entity;");
                }
            }
        } catch (Exception exception) {
            log.error("readAppointedLineNumber error", exception);
        }
        return false;
    }

    public static void forceDelete(File file) {
        if (file != null && file.exists()) {
            try {
                FileUtils.forceDelete(file);
            } catch (Exception exception) {
                log.error("forceDelete error ", exception);
            }
        }
    }
}

编译Java类

import lombok.extern.slf4j.Slf4j;

import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
import java.io.IOException;

@Slf4j
public abstract class Tools {

    /**
     * 编译java类
     *
     * @param writerPath 存放java文件的路径
     */
    public static void javac(String writerPath) {
        // java编译器
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        // 文件管理器，参数1：diagnosticListener  监听器,监听编译过程中出现的错误
        try(StandardJavaFileManager manager = compiler.getStandardFileManager(null, null, null)) {
            // java文件转换到java对象，可以是多个文件
            Iterable<? extends JavaFileObject> it = manager.getJavaFileObjects(writerPath);
            // 编译任务,可以编译多个文件
            JavaCompiler.CompilationTask tool = compiler.getTask(null, manager, null, null, null, it);
            // 执行任务
            tool.call();
        } catch (IOException exception) {
            log.error("javac error ",exception);
        }
    }
}

前端请求

handleUpload = () => {
    const { fileList, rootClass } = this.state;
    const formData = new FormData();
    fileList.forEach(file => {
      formData.append('files[]', file);
    });
    formData.append('rootClass', rootClass);

    reqwest({
      url: apiPrefix + '/biz/model/java2Schema',
      method: 'post',
      processData: false,
      data: formData,
      headers: {
        'X-CSRF-TOKEN': getCsrfToken(),
      },
      success: (data) => {
        if (data.code === 200) {
          this.setState({
            fileList: [],
            rootClass: '',
            visible: false
          });
          if (data.data) {
            this.props.dispatch({
              type: "jsonSchemaEditorVisual/changeEditorSchemaAction",
              payload: {
                value: data.data
              },
            })
          }
        } else {
          message.error("文件格式不规范，请重新上传")
        }
      },
      error: () => {
      },
    });
  };