HttpClient-APT

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Generate simple http clients with Java APT. Base on Apache HttpClient5, more efficient than the dynamic proxy (such as: OpenFeign and Forest).

Dependencies

Take gradle as an example

dependencies {
    // with gson
    implementation 'io.github.yeamy:httpclient-apt-gson:1.0.2'
    // or with jackson
    //implementation 'io.github.yeamy:httpclient-apt-jackson:1.0.2'
    // or with jackson xml
    //implementation 'io.github.yeamy:httpclient-apt-jacksonxml:1.0.2'
}

How to Use

Declared the HttpClient for interface

import yeamy.restlite.httpclient.GsonRequestAdapter;
import yeamy.restlite.httpclient.GsonResponseHandler;

@HttpClient(
        serializeAdapter = GsonRequestAdapter.class,// set request serialize adapter
        responseHandler = GsonResponseHandler.class,// set respone handler
        uri = "http://localhost:8080", // set the base uri
        maxTryTimes = 1,
        header = @Values(name = "user-agent", value = "custom-app/1.0"), // add common header
        cookie = {@Values(name = "1", value = "2"), // add common cookie
                @Values(name = "3", value = "4")})
public interface DemoClient {// must be an interface
}

Make @HttpClient into a template for multiple classes

create an annotation with HttpClient

import yeamy.restlite.httpclient.JacksonRequestAdapter;
import yeamy.restlite.httpclient.JacksonResponseHandler;

@HttpClient(
        serializeAdapter = JacksonRequestAdapter.class,
        responseHandler = JacksonResponseHandler.class,
        maxTryTimes = 1,
        uri = "http://localhost:8080",
        header = @Values(name = "user-agent", value = "custom-app/1.0"),
        cookie = {@Values(name = "1", value = "2"),
                @Values(name = "3", value = "4")})
public @interface TemplateClient {
}

add template for the interface

@TemplateClient
// @HttpClient(maxTryTimes = 2) // can also override attributes of TemplateClient
public interface DemoClient {// must be an interface
}

create request method with HttpClientRequest

public interface DemoClient {

    @HttpClientRequest(uri = "/baidu")
    Object get();
}

Declared variable (method parameter)

1. declared parameters with brackets in annotation.
2. add java method parameters with same name.

public interface DemoClient {
    @HttpClientRequest(
            uri = "http://localhost:8080/a/{u1}?x={{u2}}",
            headerMap = "{m1}",
            cookieMap = "{m2}",
            header = @Values(name = "h", value = "{h1}"),
            cookie = @Values(name = "v", value = "{c1}"),
            body = {@PartValues(name = "name", value = "{b1}")}
    )
    String getPo(String u1, String u2, String c1, String h1, String b1, Map<?, String> m1, Map<String, String> m2);
}

variable	Attribute	Usage
{u1}	uri	define a parameter for uri, the param will be encoded.
{{u2}}	uri	double brackets keep the parameter without url encoded (uri only).
{h1}	header	define a parameter for header value.
{c1}	cookie	define a parameter for cookie value.
{m1}	headerMap	define header parameters in a Map<>
{m2}	cookieMap	define cookie parameters in a Map<>
{b1}	body	define a body parameter, the body will be serialized by the adapter.

How dose the lib choose attributes

The conflicting attributes will be overridden.

attributes: serializeAdapter, responseHandler, maxTryTimes, protocol, method.

Selection order: HttpClientRequest > HttpClient > TemplateClient

Default http method:

if http method not defined(empty string), will using "GET" or "POST" (if the request contains body).

The complete uri will be the base uri append the sub uri:

base uri: HttpClient's (or TemplateClient's) uri.

sub uri: HttpClientRequest's uri.

Complete uri: base uri + sub uri.

The headers and cookies:

total: HttpClientRequest's values + HttpClient's values + TemplateClient's values.