之前写了一篇resttemplate使用实例，由于spring 5全面引入reactive，同时也有了resttemplate的reactive版webclient，本文就来对应展示下webclient的基本使用。

请求携带header

携带cookie

@test

public void testwithcookie(){

mono resp = webclient.create()

.method(httpmethod.get)

.uri("http://baidu.com")

.cookie("token","xxxx")

.cookie("jsessionid","xxxx")

.retrieve()

.bodytomono(string.class);

logger.info("result:{}",resp.block());

}

携带basic auth

@test

public void testwithbasicauth(){

string basicauth = "basic "+ base64.getencoder().encodetostring("user:pwd".getbytes(standardcharsets.utf_8));

logger.info(basicauth);

mono resp = webclient.create()

.get()

.uri("http://baidu.com")

.header(httpheaders.authorization,basicauth)

.retrieve()

.bodytomono(string.class);

logger.info("result:{}",resp.block());

}

设置全局user-agent

@test

public void testwithheaderfilter(){

webclient webclient = webclient.builder()

.defaultheader(httpheaders.user_agent, "mozilla/5.0 (macintosh; intel mac os x 10_12_6) applewebkit/537.36 (khtml, like gecko) chrome/63.0.3239.132 safari/537.36")

.filter(exchangefilterfunctions

.basicauthentication("user","password"))

.filter((clientrequest, next) -> {

logger.info("request: {} {}", clientrequest.method(), clientrequest.url());

clientrequest.headers()

.foreach((name, values) -> values.foreach(value -> logger.info("{}={}", name, value)));

return next.exchange(clientrequest);

})

.build();

mono resp = webclient.get()

.uri("https://baidu.com")

.retrieve()

.bodytomono(string.class);

logger.info("result:{}",resp.block());

}

get请求

使用placeholder传递参数

@test

public void testurlplaceholder(){

mono resp = webclient.create()

.get()

//多个参数也可以直接放到map中,参数名与placeholder对应上即可

.uri("http://www.baidu.com/s?wd={key}&other={another}","北京天气","test") //使用占位符

.retrieve()

.bodytomono(string.class);

logger.info("result:{}",resp.block());

}

使用uribuilder传递参数

@test

public void testurlbiulder(){

mono resp = webclient.create()

.get()

.uri(uribuilder -> uribuilder

.scheme("http")

.host("www.baidu.com")

.path("/s")

.queryparam("wd", "北京天气")

.queryparam("other", "test")

.build())

.retrieve()

.bodytomono(string.class);

logger.info("result:{}",resp.block());

}

post表单

@test

public void testformparam(){

multivaluemap formdata = new linkedmultivaluemap<>();

formdata.add("name1","value1");

formdata.add("name2","value2");

mono resp = webclient.create().post()

.uri("http://www.w3school.com.cn/test/demo_form.asp")

.contenttype(mediatype.application_form_urlencoded)

.body(bodyinserters.fromformdata(formdata))

.retrieve().bodytomono(string.class);

logger.info("result:{}",resp.block());

}

post json

使用bean来post

static class book {

string name;

string title;

public string getname() {

return name;

}

public void setname(string name) {

this.name = name;

}

public string gettitle() {

return title;

}

public void settitle(string title) {

this.title = title;

}

}

@test

public void testpostjson(){

book book = new book();

book.setname("name");

book.settitle("this is title");

mono resp = webclient.create().post()

.uri("http://localhost:8080/demo/json")

.contenttype(mediatype.application_json_utf8)

.body(mono.just(book),book.class)

.retrieve().bodytomono(string.class);

logger.info("result:{}",resp.block());

}

直接post raw json

@test

public void testpostrawjson(){

mono resp = webclient.create().post()

.uri("http://localhost:8080/demo/json")

.contenttype(mediatype.application_json_utf8)

.body(bodyinserters.fromobject("{\n" +

" \"title\" : \"this is title\",\n" +

" \"author\" : \"this is author\"\n" +

"}"))

.retrieve().bodytomono(string.class);

logger.info("result:{}",resp.block());

}

post二进制--上传文件

@test

public void testuploadfile(){

httpheaders headers = new httpheaders();

headers.setcontenttype(mediatype.image_png);

httpentity entity = new httpentity<>(new classpathresource("parallel.png"), headers);

multivaluemap parts = new linkedmultivaluemap<>();

parts.add("file", entity);

mono resp = webclient.create().post()

.uri("http://localhost:8080/upload")

.contenttype(mediatype.multipart_form_data)

.body(bodyinserters.frommultipartdata(parts))

.retrieve().bodytomono(string.class);

logger.info("result:{}",resp.block());

}

下载二进制

下载图片

@test

public void testdownloadimage() throws ioexception {

mono resp = webclient.create().get()

.uri("http://www.toolip.gr/captcha?complexity=99&size=60&length=9")

.accept(mediatype.image_png)

.retrieve().bodytomono(resource.class);

resource resource = resp.block();

bufferedimage bufferedimage = imageio.read(resource.getinputstream());

imageio.write(bufferedimage, "png", new file("captcha.png"));

}

下载文件

@test

public void testdownloadfile() throws ioexception {

mono resp = webclient.create().get()

.uri("http://localhost:8080/file/download")

.accept(mediatype.application_octet_stream)

.exchange();

clientresponse response = resp.block();

string disposition = response.headers().ashttpheaders().getfirst(httpheaders.content_disposition);

string filename = disposition.substring(disposition.indexof("=")+1);

resource resource = response.bodytomono(resource.class).block();

file out = new file(filename);

fileutils.copyinputstreamtofile(resource.getinputstream(),out);

logger.info(out.getabsolutepath());

}

错误处理

@test

public void testretrieve4xx(){

webclient webclient = webclient.builder()

.baseurl("https://api.github.com")

.defaultheader(httpheaders.content_type, "application/vnd.github.v3+json")

.defaultheader(httpheaders.user_agent, "spring 5 webclient")

.build();

webclient.responsespec responsespec = webclient.method(httpmethod.get)

.uri("/user/repos?sort={sortfield}&direction={sortdirection}",

"updated", "desc")

.retrieve();

mono mono = responsespec

.onstatus(e -> e.is4xxclienterror(),resp -> {

logger.error("error:{},msg:{}",resp.statuscode().value(),resp.statuscode().getreasonphrase());

return mono.error(new runtimeexception(resp.statuscode().value() + " : " + resp.statuscode().getreasonphrase()));

})

.bodytomono(string.class)

.doonerror(webclientresponseexception.class, err -> {

logger.info("error status:{},msg:{}",err.getrawstatuscode(),err.getresponsebodyasstring());

throw new runtimeexception(err.getmessage());

})

.onerrorreturn("fallback");

string result = mono.block();

logger.info("result:{}",result);

}

可以使用onstatus根据status code进行异常适配

可以使用doonerror异常适配

可以使用onerrorreturn返回默认值

小结

webclient是新一代的async rest template，api也相对简洁，而且是reactive的，非常值得使用。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持萬仟网。

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