springmvc中pom依赖：

<!-- https://mvnrepository.com/artifact/net.sf.jasperreports/jasperreports -->
        <dependency>
            <groupId>net.sf.jasperreports</groupId>
            <artifactId>jasperreports</artifactId>
            <version>6.8.0</version>
        </dependency>
        
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itextpdf</artifactId>
            <version>5.5.0</version>
        </dependency>
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itext-pdfa</artifactId>
            <version>5.5.0</version>
        </dependency>
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itext-asian</artifactId>
            <version>5.2.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.lowagie/itext -->
        <dependency>
            <groupId>com.lowagie</groupId>
            <artifactId>itext</artifactId>
            <version>2.1.7</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.codehaus.groovy/groovy-all -->
        <dependency>
          <groupId>org.codehaus.groovy</groupId>
          <artifactId>groovy-all</artifactId>
         <version>2.5.6</version>
         <type>pom</type>
        </dependency>

数据源的配置类

package top.mau5.configuration;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import java.util.HashMap;
import java.util.Map;


@Configuration
@EnableAutoConfiguration
public class DruidDBConfig {

    private Logger logger = LoggerFactory.getLogger(DruidDBConfig.class);

    @Value("${spring.datasource.url}")
    private String dbUrl;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @Value("${spring.datasource.driverClassName}")
    private String driverClassName;

//    @Value("${spring.datasource.initialSize}")
//    private int initialSize;
//
//    @Value("${spring.datasource.minIdle}")
//    private int minIdle;
//
//    @Value("${spring.datasource.maxActive}")
//    private int maxActive;
//
//    @Value("${spring.datasource.maxWait}")
//    private int maxWait;
//
//    @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
//    private int timeBetweenEvictionRunsMillis;
//
//    @Value("${spring.datasource.minEvictableIdleTimeMillis}")
//    private int minEvictableIdleTimeMillis;
//
//    @Value("${spring.datasource.validationQuery}")
//    private String validationQuery;
//
//    @Value("${spring.datasource.testWhileIdle}")
//    private boolean testWhileIdle;
//
//    @Value("${spring.datasource.testOnBorrow}")
//    private boolean testOnBorrow;
//
//    @Value("${spring.datasource.testOnReturn}")
//    private boolean testOnReturn;
//
//    @Value("${spring.datasource.poolPreparedStatements}")
//    private boolean poolPreparedStatements;
//
//    @Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
//    private int maxPoolPreparedStatementPerConnectionSize;
//
//    @Value("${spring.datasource.filters}")
//    private String filters;
//
//    @Value("{spring.datasource.connectionProperties}")
//    private String connectionProperties;

    @Bean     //声明其为Bean实例
    @Primary  //在同样的DataSource中，首先使用被标注的DataSource
    public DruidDataSource dataSource(){
        DruidDataSource datasource = new DruidDataSource();

        datasource.setUrl(this.dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);

//        //configuration
//        datasource.setInitialSize(initialSize);
//        datasource.setMinIdle(minIdle);
//        datasource.setMaxActive(maxActive);
//        datasource.setMaxWait(maxWait);
//        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
//        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
//        datasource.setValidationQuery(validationQuery);
//        datasource.setTestWhileIdle(testWhileIdle);
//        datasource.setTestOnBorrow(testOnBorrow);
//        datasource.setTestOnReturn(testOnReturn);
//        datasource.setPoolPreparedStatements(poolPreparedStatements);
//        datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
//        try {
//            datasource.setFilters(filters);
//        } catch (SQLException e) {
//            logger.error("druid configuration initialization filter", e);
//        }
//        datasource.setConnectionProperties(connectionProperties);

        return datasource;
    }

    @Bean
    public ServletRegistrationBean druidServletRegistrationBean() {
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean();
        servletRegistrationBean.setServlet(new StatViewServlet());
        servletRegistrationBean.addUrlMappings("/druid/*");
        return servletRegistrationBean;
    }

    /**
     * 注册DruidFilter拦截
     *
     * @return
     */
    
    @Bean
    public FilterRegistrationBean duridFilterRegistrationBean() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new WebStatFilter());
        Map<String, String> initParams = new HashMap<String, String>();
        //设置忽略请求
        initParams.put("exclusions", "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*");
        filterRegistrationBean.setInitParameters(initParams);
        filterRegistrationBean.addUrlPatterns("/*");
        return filterRegistrationBean;
    }

}

controller:

@RequestMapping(value = "report")
@RestController
public class ReportController {
    
    @Autowired
    DruidDataSource druidDataSource;
    
    @Autowired
    ReportService reportService;
    
    public static final String ROOT_PATH = "C:\\Users\\korin\\Desktop\\jaspertest\\";//本机文件保存地址
//  public static final String ROOT_PATH = "C:\\jaspertest\\";//云服务器文件保存地址
    
    @RequestMapping("uploadJrxml")
    public Map<String,Object> fileUpload(MultipartFile file) throws IllegalStateException, IOException{
        System.out.println(file.getOriginalFilename());
        Filepath filepath = new Filepath();
        filepath.setName(file.getOriginalFilename());
        filepath.setPath(ROOT_PATH+filepath.getName());
        file.transferTo(new File(filepath.getPath()));
        
        reportService.insesrt(filepath);
        Map<String,Object> map = new HashMap<>();
        map.put("msg", "ok");
        map.put("uuid", filepath.getRid());
        return map;
    }
    
    @RequestMapping("showfilelist")
    public List<Filepath> showfilelist() throws IllegalStateException, IOException{
        return reportService.select(new Filepath());
    }
    /**
     * 通过jrxml文件生成html，参数固定测试版
     * 
     * 在这之前应该有个上传jrxml文件功能，上传到指定文件夹，存数据库（uuid,存储路径等）后返回uuid
     * 
     * @param jrxml_path jrxml存放路径
     * @param id 主键id
     * @return
     * @throws JRException 
     * @throws IOException 
     * @throws UnsupportedEncodingException 
     */
    @RequestMapping(value = "jrxml2html",produces = "text/html;charset=UTF-8")/* 返回格式为text/html */
    public String  jrxml2html(HttpServletRequest request,String jrxmlName,String id) throws JRException, UnsupportedEncodingException, IOException {
        
        JasperReport jasper = JasperCompileManager.compileReport(new FileInputStream(new File("C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".jrxml")));
        
        Map<String,Object> map = new HashMap<>();
        map.put("P_YHTZID", id);
        Connection conn = null;
        String str = "";
        try {
            /* 生成html文件 */
            conn = druidDataSource.getConnection();
            JasperPrint jasperPrint = JasperFillManager.fillReport(jasper,map,conn);
            JasperExportManager.exportReportToHtmlFile(jasperPrint,"C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".html");
            
            /* 读取html文件 */
            URL url = new URL("file:\\C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".html");
            BufferedReader br = null;
            br = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
            String res;
            StringBuilder sb = new StringBuilder("");
            while ((res = br.readLine()) != null) {
                sb.append(res.trim());
            }
            str = sb.toString();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return str;
    }
    
    //参数可变
    @RequestMapping(value = "jrxml2html_",produces = "text/html;charset=UTF-8")/* 返回格式为text/html */
    public String  jrxml2html_(HttpServletRequest request) throws JRException, UnsupportedEncodingException, IOException {
        Map<String,Object> map = getParameterMap(request);
        String jrxmlName = map.get("jrxmlName").toString();
        //,String jrxmlName,String paramId
        JasperReport jasper = JasperCompileManager.compileReport(new FileInputStream(new File("C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".jrxml")));
//      map.put("P_YHTZID", id);
        Connection conn = null;
        String str = "";
        try {
            /* 生成html文件 */
            conn = druidDataSource.getConnection();
            JasperPrint jasperPrint = JasperFillManager.fillReport(jasper,map,conn);
            JasperExportManager.exportReportToHtmlFile(jasperPrint,"C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".html");
            
            /* 读取html文件 */
            URL url = new URL("file:\\C:\\Users\\korin\\Desktop\\jaspertest\\"+jrxmlName+".html");
            BufferedReader br = null;
            br = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
            String res;
            StringBuilder sb = new StringBuilder("");
            while ((res = br.readLine()) != null) {
                sb.append(res.trim());
            }
            str = sb.toString();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return str;
    }
    
    //优化后
    /**
     * @param request   参数中要带rid（在数据库filepath表中的rid）和相应的报表中所需的参数名和值（如P_YHTZID=...）
     * @return
     * @throws JRException
     * @throws UnsupportedEncodingException
     * @throws IOException
     */
    @RequestMapping(value = "jrxml2html__",produces = "text/html;charset=UTF-8")/* 返回格式为text/html */
    public String  jrxml2html__(HttpServletRequest request) throws JRException, UnsupportedEncodingException, IOException {
        Filepath filepath = new Filepath();
        Map<String,Object> map = getParameterMap(request);
        filepath.setRid(map.get("rid").toString());
        String filePath = reportService.select(filepath).get(0).getPath();
        InputStream is = new FileInputStream(new File(filePath));
        JasperReport jasper = JasperCompileManager.compileReport(is);
        Connection conn = null;
        String str = "";
        filePath = filePath.replaceAll(".jrxml", ".html");//html文件路径
        try {
            /* 生成html文件 */
            File file = new File(filePath);
            if(file.exists()) {
                file.delete();//删除以前的html文件
            }
            conn = druidDataSource.getConnection();
            JasperPrint jasperPrint = JasperFillManager.fillReport(jasper,map,conn);
            JasperExportManager.exportReportToHtmlFile(jasperPrint,filePath);
            
            /* 读取html文件 */
            URL url = new URL("file:\\"+filePath);
            BufferedReader br = null;
            br = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
            String res;
            StringBuilder sb = new StringBuilder("");
            while ((res = br.readLine()) != null) {
                sb.append(res.trim());
            }
            str = sb.toString();
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            try {
                is.close();//关流
                conn.close();//关闭数据库连接
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return str;
    }

    protected Map<String, Object> getParameterMap(HttpServletRequest request) {
        return getParameterMap(request, false);
    }

    protected Map<String, Object> getParameterMap(HttpServletRequest request, boolean needNull) {
        Map<String, Object> map = new HashMap<String, Object>();
        Map<String, String[]> parameterMap = request.getParameterMap();
        for (String paramName : parameterMap.keySet()) {
            String[] paramValues = parameterMap.get(paramName);
            if (null != paramValues && paramValues.length > 1) {
                map.put(paramName, paramValues);
            } else if (null != paramValues) {
                String paramValue = parameterMap.get(paramName)[0];
                if (StringUtils.isNotEmpty(paramValue) || needNull) {
                    map.put(paramName, paramValue);
                }
            }
        }
        return map;
    }
}