我得到了这样的URI:
https://google.com.ua/oauth/authorize?client_id=SS&response_type=code&scope=N_FULL&access_type=offline&redirect_uri=http://localhost/Callback
我需要一个包含已解析元素的集合:
NAME VALUE
------------------------
client_id SS
response_type code
scope N_FULL
access_type offline
redirect_uri http://localhost/Callback
确切地说，我需要一个与c# /等价的Java。净HttpUtility。ParseQueryString方法。
当前回答
在我看来，这是最好的方法:
static Map<String, String> decomposeQueryString(String query, Charset charset) {
return Arrays.stream(query.split("&"))
.map(pair -> pair.split("=", 2))
.collect(Collectors.toMap(
pair -> URLDecoder.decode(pair[0], charset),
pair -> pair.length > 1 ? URLDecoder.decode(pair[1], charset) : null)
);
}
前提条件是查询语法不允许重复参数。
其他回答
一个kotlin版本
由马提亚提供的答案
fun decomposeQueryString(query: String, charset: Charset): Map<String, String?> {
return if (query.split("?").size <= 1)
emptyMap()
else {
query.split("?")[1]
.split("&")
.map { it.split(Pattern.compile("="), 2) }
.associate {
Pair(
URLDecoder.decode(it[0], charset.name()),
if (it.size > 1) URLDecoder.decode(it[1], charset.name()) else null
)
}
}
}
这需要问号'?’。
有一个新版本的Apache HTTP客户端- org.apache.httpcomponents。client5 -其中URLEncodedUtils现在已弃用。应该改为使用URIBuilder:
import org.apache.hc.core5.http.NameValuePair;
import org.apache.hc.core5.net.URIBuilder;
private static Map<String, String> getQueryParameters(final String url) throws URISyntaxException {
return new URIBuilder(new URI(url), StandardCharsets.UTF_8).getQueryParams()
.stream()
.collect(Collectors.toMap(NameValuePair::getName,
nameValuePair -> URLDecoder.decode(nameValuePair.getValue(), StandardCharsets.UTF_8)));
}
在我看来，这是最好的方法:
static Map<String, String> decomposeQueryString(String query, Charset charset) {
return Arrays.stream(query.split("&"))
.map(pair -> pair.split("=", 2))
.collect(Collectors.toMap(
pair -> URLDecoder.decode(pair[0], charset),
pair -> pair.length > 1 ? URLDecoder.decode(pair[1], charset) : null)
);
}
前提条件是查询语法不允许重复参数。
用谷歌番石榴，分成两行:
import java.util.Map;
import com.google.common.base.Splitter;
public class Parser {
public static void main(String... args) {
String uri = "https://google.com.ua/oauth/authorize?client_id=SS&response_type=code&scope=N_FULL&access_type=offline&redirect_uri=http://localhost/Callback";
String query = uri.split("\\?")[1];
final Map<String, String> map = Splitter.on('&').trimResults().withKeyValueSeparator('=').split(query);
System.out.println(map);
}
}
这让你
{client_id=SS, response_type=code, scope=N_FULL, access_type=offline, redirect_uri=http://localhost/Callback}
一种现成的URI查询部分解码解决方案(包括解码和多参数值)
评论
我对https://stackoverflow.com/a/13592567/1211082中@Pr0gr4mm3r提供的代码不满意。基于流的解决方案不做URLDecoding，可变版本的笨拙。
因此，我阐述了一个解决方案
Can decompose a URI query part into a Map<String, List<Optional<String>>> Can handle multiple values for the same parameter name Can represent parameters without a value properly (Optional.empty() instead of null) Decodes parameter names and values correctly via URLdecode Is based on Java 8 Streams Is directly usable (see code including imports below) Allows for proper error handling (here via turning a checked exception UnsupportedEncodingExceptioninto a runtime exception RuntimeUnsupportedEncodingException that allows interplay with stream. (Wrapping regular function into functions throwing checked exceptions is a pain. And Scala Try is not available in the Java language default.)
Java代码
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.*;
import static java.util.stream.Collectors.*;
public class URIParameterDecode {
/**
* Decode parameters in query part of a URI into a map from parameter name to its parameter values.
* For parameters that occur multiple times each value is collected.
* Proper decoding of the parameters is performed.
*
* Example
* <pre>a=1&b=2&c=&a=4</pre>
* is converted into
* <pre>{a=[Optional[1], Optional[4]], b=[Optional[2]], c=[Optional.empty]}</pre>
* @param query the query part of an URI
* @return map of parameters names into a list of their values.
*
*/
public static Map<String, List<Optional<String>>> splitQuery(String query) {
if (query == null || query.isEmpty()) {
return Collections.emptyMap();
}
return Arrays.stream(query.split("&"))
.map(p -> splitQueryParameter(p))
.collect(groupingBy(e -> e.get0(), // group by parameter name
mapping(e -> e.get1(), toList())));// keep parameter values and assemble into list
}
public static Pair<String, Optional<String>> splitQueryParameter(String parameter) {
final String enc = "UTF-8";
List<String> keyValue = Arrays.stream(parameter.split("="))
.map(e -> {
try {
return URLDecoder.decode(e, enc);
} catch (UnsupportedEncodingException ex) {
throw new RuntimeUnsupportedEncodingException(ex);
}
}).collect(toList());
if (keyValue.size() == 2) {
return new Pair(keyValue.get(0), Optional.of(keyValue.get(1)));
} else {
return new Pair(keyValue.get(0), Optional.empty());
}
}
/** Runtime exception (instead of checked exception) to denote unsupported enconding */
public static class RuntimeUnsupportedEncodingException extends RuntimeException {
public RuntimeUnsupportedEncodingException(Throwable cause) {
super(cause);
}
}
/**
* A simple pair of two elements
* @param <U> first element
* @param <V> second element
*/
public static class Pair<U, V> {
U a;
V b;
public Pair(U u, V v) {
this.a = u;
this.b = v;
}
public U get0() {
return a;
}
public V get1() {
return b;
}
}
}
Scala代码
．.． 为了完整起见，我忍不住要用Scala提供简洁美观的解决方案
import java.net.URLDecoder
object Decode {
def main(args: Array[String]): Unit = {
val input = "a=1&b=2&c=&a=4";
println(separate(input))
}
def separate(input: String) : Map[String, List[Option[String]]] = {
case class Parameter(key: String, value: Option[String])
def separateParameter(parameter: String) : Parameter =
parameter.split("=")
.map(e => URLDecoder.decode(e, "UTF-8")) match {
case Array(key, value) => Parameter(key, Some(value))
case Array(key) => Parameter(key, None)
}
input.split("&").toList
.map(p => separateParameter(p))
.groupBy(p => p.key)
.mapValues(vs => vs.map(p => p.value))
}
}
