Doc doc = new SimpleDoc(new FileInputStream("tobeprint.pdf"), DocFlavor.BYTE_ARRAY.PDF, null);
PrintService ps = PrintServiceLookup.lookupDefaultPrintService();
DocPrintJob job = ps.createPrintJob();
job.print(doc, null);

import java.awt.*;
import java.awt.print.*;


public class PrintToPrinter {

    public static void main(String[] args) throws Exception {
        Book book = new Book();
        PageFormat pf = new PageFormat();
        pf.setOrientation(PageFormat.PORTRAIT);

        Paper p = new Paper();
        p.setSize(590, 840);
        p.setImageableArea(10, 10, 590, 840);
        pf.setPaper(p);
        book.append(new OneLabel(), pf);

        PrinterJob job = PrinterJob.getPrinterJob();
        job.setPageable(book);
        job.print();
    }

    /**
     * 实现Printable即可打印
     */
    public static class OneLabel implements Printable {
        @Override
        public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
            if (pageIndex != 0) {
                // 此例子只有一页；
                return NO_SUCH_PAGE;
            }
            Graphics2D g2 = (Graphics2D) graphics;
            double scale = 72.0 / 300; //屏幕DPI是72；打印机DPI：300； 可以实现打印的更精细，特别是图片
            g2.scale(scale, scale);

            g2.setColor(Color.black);

            double x = pageFormat.getImageableX();
            double y = pageFormat.getImageableY();
            System.out.println("左上角：" + x + "," + y + "  宽高: " + pageFormat.getWidth() + "," + pageFormat.getHeight());

            String str = "中文字符串";
            Font font = new Font("微软雅黑", Font.PLAIN, 10);
            g2.setFont(font);
            g2.drawString(str, (float) x, (float) (y + 20));

            Font font2 = new Font("微软雅黑", Font.PLAIN, 20);
            g2.setFont(font2);
            g2.drawString(str, (float) x, (float) (y + 80));

            return PAGE_EXISTS;
        }
    }
}

final Canvas canvas = new Canvas(250,250);
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.fillText("hello, world.", 10, 10);
PrinterJob printerJob = PrinterJob.createPrinterJob();
printerJob.printPage(canvas);

@PostMapping(consumes = {MediaType.TEXT_XML_VALUE}, 
             produces = {MediaType.TEXT_XML_VALUE})

@PostMapping(consumes = {MediaType.TEXT_XML_VALUE}, 
             produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.TEXT_XML_VALUE})

@PostMapping(consumes = {MediaType.TEXT_XML_VALUE}, 
             produces = {MediaType.TEXT_XML_VALUE, MediaType.APPLICATION_JSON_VALUE})

@Configuration
public class WebAppConfigurer extends WebMvcConfigurationSupport {

    @Override
    protected void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        // 这里设置默认的返回格式
        configurer.defaultContentType(MediaType.APPLICATION_JSON);
    }

}

@Configuration
public class MultipartConfig {

    @Bean
    MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        String tempLocation = "c:\\temp";
        File tmpFile = new File(tempLocation);
        if (!tmpFile.exists()) {
            tmpFile.mkdirs();
        }
        factory.setLocation(tempLocation);
        return factory.createMultipartConfig();
    }
}

import java.io.File;
import java.lang.reflect.Method;
import java.net.URI;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Arrays;

import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.ToolProvider;

public class DynamicCompiler{

    /**
     * 动态编译传入的类源码并返回编译好的类
     */
    public Class compile(String sourceCode) throws Exception{
        File distDir = new File("target");
        if (!distDir.exists()) {
            distDir.mkdirs();
        }
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        String className = getFullClassNameFromCode(sourceCode);
        JavaFileObject javaFileObject = new CodeJavaFileObject(className, sourceCode);
        JavaCompiler.CompilationTask task = compiler.getTask(null, null, null,
                Arrays.asList("-d", distDir.getAbsolutePath()), null,
                Arrays.asList(javaFileObject));
        boolean compileSuccess = task.call();
        if (!compileSuccess) {
            System.out.println("compile failed");
            return null;
        } else {
            //动态执行 (反射执行)
            System.out.println("compile successed " + distDir.getAbsolutePath());
            //URL 需要以 file:// 开始； 如果是目录需要以 / 结束；也可以是jar
            URL[] urls = new URL[] {new URL("file://" + distDir.getAbsolutePath() + "/")};
            URLClassLoader classLoader = new URLClassLoader(urls);
            Class dynamicClass = classLoader.loadClass(className);
            return dynamicClass;
        }
    }


    class CodeJavaFileObject extends SimpleJavaFileObject{
        private String code;

        public CodeJavaFileObject(String className, String code){
            super(URI.create(className.replaceAll("\\.", "/") + Kind.SOURCE.extension), Kind.SOURCE);
            this.code = code;
        }

        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return code;
        }
    }

    private String getFullClassNameFromCode(String code){
        String t = code.substring(0, code.indexOf('{'));
        String s = t.replaceAll("[\r\n\t]", " ").trim();
        String[] ary = s.split("[;]");
        String packageName = null;
        String className = getLastPart((ary[ary.length - 1]));
        if(ary[0].startsWith("package ")){
            packageName = getLastPart(ary[0]);
            return packageName + "." + className;
        }else{
            return className;
        }
    }

    private String getLastPart(String s){
        String[] ary = s.trim().split(" ");
        return ary[ary.length - 1];
    }

    public static void main(String[] argvs) throws Exception{
        StringBuffer buf = new StringBuffer();
        buf.append("package a.b.c;\r\npublic class ANumber{")
                .append("public int getNumber() {")
                .append("System.out.println(\"Hello World in getNumber()!\"); return 999;")
                .append("}")
                .append("}");

        DynamicCompiler dc = new DynamicCompiler();
        Class cls = dc.compile(buf.toString());
        System.out.println(cls.getName());
        Object obj = cls.getDeclaredConstructor().newInstance();
        Method method = cls.getDeclaredMethod("getNumber");
        Object r = method.invoke(obj);
        System.out.println("result is " + r);
    }
}

/** 生成JWT **/
public String createToken(String name, String userId, String email) throws IllegalArgumentException, UnsupportedEncodingException{
    JWTCreator.Builder builder = JWT.create();
    Algorithm algorithm = Algorithm.HMAC256("xxxxx"); //另外一端解析时也需要这个密码
    String token = builder.withClaim("name", name.withClaim("user_id", userId).withClaim("email", email)
                    .withExpiresAt(new Date(new Date().getTime() + 24*3600*1000)).sign(algorithm);
    return token;
}

/** 解析JWT **/
public User parseJwt(String token){
    User = new User();
    try {
        Algorithm algorithm = Algorithm.HMAC256("xxxxx"); // 另外一端解析时也需要这个密码
        JWTVerifier verifier = JWT.require(algorithm).acceptExpiresAt(5).build(); // Reusable verifier instance
        DecodedJWT jwt = verifier.verify(token);
        String userId = jwt.getClaim("user_id").asString();
        String name = jwt.getClaim("name").asString();
        String email = jwt.getClaim("email").asString();
        user.setId(userId);
        user.setName(name);
        user.setEmail(email);
    } catch (JWTVerificationException | IllegalArgumentException | UnsupportedEncodingException e) {
        log.error("无效的token" + token, e);
        return null;
    } catch (Throwable e) {
        log.error("验证token异常：" + token, e);
        return null;
    }
    return user;
}

/**
 * 被创建的类的例子，也可以是抽象类
 */
public class MyClass {
private String name;
public String getName() {
return name;
    }
public void setName(String name) {
this.name = name;
    }
}

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
/**
 * 使用CGLIB动态生成一个类的子类的例子
 */
public class MyClassProxy {
public static void main(String[] argvs) throws Exception{
MyClass mc = createDefaultImplementation(MyClass.class);
        mc.setName("waytt");
System.out.println(mc.getName());
    }
public static <A> A createDefaultImplementation(Class<A> abstractClass) {
Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(abstractClass);
        enhancer.setCallback(new MethodInterceptor() {
public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
System.out.println("MethodInterceptor.intercept(proxy, " + method.getName() + ",...)");
if (!Modifier.isAbstract(method.getModifiers())) {
//not abstract method, 可调用类的方法并返回
return methodProxy.invokeSuper(proxy, args);
                } else {
// 抽象方法，不能执行父类的方法了，需要自己构建一个返回值
System.out.println("abstract method....");
Class type = method.getReturnType();
// 生成返回值
return null；
                }
            }
        });
return (A) enhancer.create();
    }
public static <A> A createDefaultImplementation(String className) throws ClassNotFoundException{
return (A) createDefaultImplementation(Class.forName(className));
    }
}