feign.RequestTemplate Maven / Gradle / Ivy
/*
* Copyright 2013 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package feign;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import static feign.Util.CONTENT_LENGTH;
import static feign.Util.UTF_8;
import static feign.Util.checkNotNull;
import static feign.Util.emptyToNull;
import static feign.Util.toArray;
import static feign.Util.valuesOrEmpty;
/**
* Builds a request to an http target. Not thread safe.
*
*
relationship to JAXRS 2.0
*
* A combination of {@code javax.ws.rs.client.WebTarget} and
* {@code javax.ws.rs.client.Invocation.Builder}, ensuring you can modify any
* part of the request. However, this object is mutable, so needs to be guarded
* with the copy constructor.
*/
public final class RequestTemplate implements Serializable {
interface Factory {
/** create a request template using args passed to a method invocation. */
RequestTemplate create(Object[] argv);
}
private String method;
/* final to encourage mutable use vs replacing the object. */
private StringBuilder url = new StringBuilder();
private final Map> queries = new LinkedHashMap>();
private final Map> headers = new LinkedHashMap>();
private transient Charset charset;
private byte[] body;
private String bodyTemplate;
public RequestTemplate() {
}
/* Copy constructor. Use this when making templates. */
public RequestTemplate(RequestTemplate toCopy) {
checkNotNull(toCopy, "toCopy");
this.method = toCopy.method;
this.url.append(toCopy.url);
this.queries.putAll(toCopy.queries);
this.headers.putAll(toCopy.headers);
this.charset = toCopy.charset;
this.body = toCopy.body;
this.bodyTemplate = toCopy.bodyTemplate;
}
/**
* Resolves any template parameters in the requests path, query, or headers
* against the supplied unencoded arguments.
*
*
relationship to JAXRS 2.0
*
* This call is similar to
* {@code javax.ws.rs.client.WebTarget.resolveTemplates(templateValues, true)}
* , except that the template values apply to any part of the request, not
* just the URL
*/
public RequestTemplate resolve(Map unencoded) {
replaceQueryValues(unencoded);
Map encoded = new LinkedHashMap();
for (Entry entry : unencoded.entrySet()) {
encoded.put(entry.getKey(), urlEncode(String.valueOf(entry.getValue())));
}
String resolvedUrl = expand(url.toString(), encoded).replace("%2F", "/");
url = new StringBuilder(resolvedUrl);
Map> resolvedHeaders = new LinkedHashMap>();
for (String field : headers.keySet()) {
Collection resolvedValues = new ArrayList();
for (String value : valuesOrEmpty(headers, field)) {
String resolved;
if (value.indexOf('{') == 0) {
resolved = String.valueOf(unencoded.get(field));
} else {
resolved = value;
}
if (resolved != null)
resolvedValues.add(resolved);
}
resolvedHeaders.put(field, resolvedValues);
}
headers.clear();
headers.putAll(resolvedHeaders);
if (bodyTemplate != null)
body(urlDecode(expand(bodyTemplate, unencoded)));
return this;
}
/* roughly analogous to {@code javax.ws.rs.client.Target.request()}. */
public Request request() {
return new Request(method, new StringBuilder(url).append(queryLine()).toString(),
headers, body, charset);
}
private static String urlDecode(String arg) {
try {
return URLDecoder.decode(arg, UTF_8.name());
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private static String urlEncode(Object arg) {
try {
return URLEncoder.encode(String.valueOf(arg), UTF_8.name());
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
/**
* Expands a {@code template}, such as {@code username}, using the {@code variables} supplied. Any unresolved
* parameters will remain.
*
* Note that if you'd like curly braces literally in the {@code template},
* urlencode them first.
*
* @param template URI template that can be in level 1 RFC6570 form.
* @param variables to the URI template
* @return expanded template, leaving any unresolved parameters literal
*/
public static String expand(String template, Map variables) {
// skip expansion if there's no valid variables set. ex. {a} is the
// first valid
if (checkNotNull(template, "template").length() < 3)
return template.toString();
checkNotNull(variables, "variables for %s", template);
boolean inVar = false;
StringBuilder var = new StringBuilder();
StringBuilder builder = new StringBuilder();
for (char c : template.toCharArray()) {
switch (c) {
case '{':
inVar = true;
break;
case '}':
inVar = false;
String key = var.toString();
Object value = variables.get(var.toString());
if (value != null)
builder.append(value);
else
builder.append('{').append(key).append('}');
var = new StringBuilder();
break;
default:
if (inVar)
var.append(c);
else
builder.append(c);
}
}
return builder.toString();
}
/* @see Request#method() */
public RequestTemplate method(String method) {
this.method = checkNotNull(method, "method");
return this;
}
/* @see Request#method() */
public String method() {
return method;
}
/* @see #url() */
public RequestTemplate append(CharSequence value) {
url.append(value);
url = pullAnyQueriesOutOfUrl(url);
return this;
}
/* @see #url() */
public RequestTemplate insert(int pos, CharSequence value) {
url.insert(pos, pullAnyQueriesOutOfUrl(new StringBuilder(value)));
return this;
}
public String url() {
return url.toString();
}
/**
* Replaces queries with the specified {@code configKey} with url decoded
* {@code values} supplied.
*
* When the {@code value} is {@code null}, all queries with the {@code configKey}
* are removed.
*
*
relationship to JAXRS 2.0
*
* Like {@code WebTarget.query}, except the values can be templatized.
*
* ex.
*
*
* template.query("Signature", "{signature}");
*
*
* @param configKey the configKey of the query
* @param values can be a single null to imply removing all values. Else no
* values are expected to be null.
* @see #queries()
*/
public RequestTemplate query(String configKey, String... values) {
queries.remove(checkNotNull(configKey, "configKey"));
if (values != null && values.length > 0 && values[0] != null) {
ArrayList encoded = new ArrayList();
for (String value : values) {
encoded.add(encodeIfNotVariable(value));
}
this.queries.put(encodeIfNotVariable(configKey), encoded);
}
return this;
}
/* @see #query(String, String...) */
public RequestTemplate query(String configKey, Iterable values) {
if (values != null)
return query(configKey, toArray(values, String.class));
return query(configKey, (String[]) null);
}
private String encodeIfNotVariable(String in) {
if (in == null || in.indexOf('{') == 0)
return in;
return urlEncode(in);
}
/**
* Replaces all existing queries with the newly supplied url decoded
* queries.
*
*
relationship to JAXRS 2.0
*
* Like {@code WebTarget.queries}, except the values can be templatized.
*
* ex.
*
*
* template.queries(ImmutableMultimap.of("Signature", "{signature}"));
*
*
* @param queries if null, remove all queries. else value to replace all queries
* with.
* @see #queries()
*/
public RequestTemplate queries(Map> queries) {
if (queries == null || queries.isEmpty()) {
this.queries.clear();
} else {
for (Entry> entry : queries.entrySet())
query(entry.getKey(), toArray(entry.getValue(), String.class));
}
return this;
}
/**
* Returns an immutable copy of the url decoded queries.
*
* @see Request#url()
*/
public Map> queries() {
Map> decoded = new LinkedHashMap>();
for (String field : queries.keySet()) {
Collection decodedValues = new ArrayList();
for (String value : valuesOrEmpty(queries, field)) {
if (value != null) {
decodedValues.add(urlDecode(value));
} else {
decodedValues.add(null);
}
}
decoded.put(urlDecode(field), decodedValues);
}
return Collections.unmodifiableMap(decoded);
}
/**
* Replaces headers with the specified {@code configKey} with the
* {@code values} supplied.
*
* When the {@code value} is {@code null}, all headers with the {@code configKey}
* are removed.
*
*
relationship to JAXRS 2.0
*
* Like {@code WebTarget.queries} and {@code javax.ws.rs.client.Invocation.Builder.header},
* except the values can be templatized.
*
* ex.
*
*
* template.query("X-Application-Version", "{version}");
*
*
* @param name the name of the header
* @param values can be a single null to imply removing all values. Else no
* values are expected to be null.
* @see #headers()
*/
public RequestTemplate header(String name, String... values) {
checkNotNull(name, "header name");
if (values == null || (values.length == 1 && values[0] == null)) {
headers.remove(name);
} else {
List headers = new ArrayList();
headers.addAll(Arrays.asList(values));
this.headers.put(name, headers);
}
return this;
}
/* @see #header(String, String...) */
public RequestTemplate header(String name, Iterable values) {
if (values != null)
return header(name, toArray(values, String.class));
return header(name, (String[]) null);
}
/**
* Replaces all existing headers with the newly supplied headers.
*
*
relationship to JAXRS 2.0
*
* Like {@code Invocation.Builder.headers(MultivaluedMap)}, except the
* values can be templatized.
*
* ex.
*
*
* template.headers(ImmutableMultimap.of("X-Application-Version", "{version}"));
*
*
* @param headers if null, remove all headers. else value to replace all headers
* with.
* @see #headers()
*/
public RequestTemplate headers(Map> headers) {
if (headers == null || headers.isEmpty())
this.headers.clear();
else
this.headers.putAll(headers);
return this;
}
/**
* Returns an immutable copy of the current headers.
*
* @see Request#headers()
*/
public Map> headers() {
return Collections.unmodifiableMap(headers);
}
/**
* replaces the {@link feign.Util#CONTENT_LENGTH} header.
*
* Usually populated by an {@link feign.codec.Encoder}.
*
* @see Request#body()
*/
public RequestTemplate body(byte[] bodyData, Charset charset) {
this.bodyTemplate = null;
this.charset = charset;
this.body = bodyData;
int bodyLength = bodyData != null ? bodyData.length : 0;
header(CONTENT_LENGTH, String.valueOf(bodyLength));
return this;
}
/**
* replaces the {@link feign.Util#CONTENT_LENGTH} header.
*
* Usually populated by an {@link feign.codec.Encoder}.
*
* @see Request#body()
*/
public RequestTemplate body(String bodyText) {
byte[] bodyData = bodyText != null ? bodyText.getBytes(UTF_8) : null;
return body(bodyData, UTF_8);
}
/**
* The character set with which the body is encoded, or null if unknown or not applicable. When this is
* present, you can use {@code new String(req.body(), req.charset())} to access the body as a String.
*/
public Charset charset() {
return charset;
}
/**
* @see Request#body()
*/
public byte[] body() {
return body;
}
/**
* populated by {@link Body}
*
* @see Request#body()
*/
public RequestTemplate bodyTemplate(String bodyTemplate) {
this.bodyTemplate = bodyTemplate;
this.charset = null;
this.body = null;
return this;
}
/**
* @see Request#body()
* @see #expand(String, Map)
*/
public String bodyTemplate() {
return bodyTemplate;
}
/**
* if there are any query params in the URL, this will extract them out.
*/
private StringBuilder pullAnyQueriesOutOfUrl(StringBuilder url) {
// parse out queries
int queryIndex = url.indexOf("?");
if (queryIndex != -1) {
String queryLine = url.substring(queryIndex + 1);
Map> firstQueries = parseAndDecodeQueries(queryLine);
if (!queries.isEmpty()) {
firstQueries.putAll(queries);
queries.clear();
}
//Since we decode all queries, we want to use the
//query()-method to re-add them to ensure that all
//logic (such as url-encoding) are executed, giving
//a valid queryLine()
for(String key : firstQueries.keySet()) {
Collection values = firstQueries.get(key);
if(allValuesAreNull(values)) {
//Queryies where all values are null will
//be ignored by the query(key, value)-method
//So we manually avoid this case here, to ensure that
//we still fulfill the contract (ex. parameters without values)
queries.put(urlEncode(key), values);
}
else {
query(key, values);
}
}
return new StringBuilder(url.substring(0, queryIndex));
}
return url;
}
private boolean allValuesAreNull(Collection values) {
if(values.isEmpty()) return true;
for(String val : values) {
if(val != null) return false;
}
return true;
}
private static Map> parseAndDecodeQueries(String queryLine) {
Map> map = new LinkedHashMap>();
if (emptyToNull(queryLine) == null)
return map;
if (queryLine.indexOf('&') == -1) {
if (queryLine.indexOf('=') != -1)
putKV(queryLine, map);
else
map.put(queryLine, null);
} else {
char[] chars = queryLine.toCharArray();
int start = 0;
int i = 0;
for (; i < chars.length; i++) {
if (chars[i] == '&') {
putKV(queryLine.substring(start, i), map);
start = i + 1;
}
}
putKV(queryLine.substring(start, i), map);
}
return map;
}
private static void putKV(String stringToParse, Map> map) {
String key;
String value;
// note that '=' can be a valid part of the value
int firstEq = stringToParse.indexOf('=');
if (firstEq == -1) {
key = urlDecode(stringToParse);
value = null;
} else {
key = urlDecode(stringToParse.substring(0, firstEq));
value = urlDecode(stringToParse.substring(firstEq + 1));
}
Collection values = map.containsKey(key) ? map.get(key) : new ArrayList();
values.add(value);
map.put(key, values);
}
@Override public String toString() {
return request().toString();
}
/**
* Replaces query values which are templated with corresponding values from the {@code unencoded} map.
* Any unresolved queries are removed.
*/
public void replaceQueryValues(Map unencoded) {
Iterator>> iterator = queries.entrySet().iterator();
while (iterator.hasNext()) {
Entry> entry = iterator.next();
if (entry.getValue() == null) {
continue;
}
Collection values = new ArrayList();
for (String value : entry.getValue()) {
if (value.indexOf('{') == 0 && value.indexOf('}') == value.length() - 1) {
Object variableValue = unencoded.get(value.substring(1, value.length() - 1));
// only add non-null expressions
if (variableValue == null) {
continue;
}
if (variableValue instanceof Iterable) {
for (Object val : Iterable.class.cast(variableValue)) {
values.add(urlEncode(String.valueOf(val)));
}
} else {
values.add(urlEncode(String.valueOf(variableValue)));
}
} else {
values.add(value);
}
}
if (values.isEmpty()) {
iterator.remove();
} else {
entry.setValue(values);
}
}
}
public String queryLine() {
if (queries.isEmpty())
return "";
StringBuilder queryBuilder = new StringBuilder();
for (String field : queries.keySet()) {
for (String value : valuesOrEmpty(queries, field)) {
queryBuilder.append('&');
queryBuilder.append(field);
if (value != null) {
queryBuilder.append('=');
if (!value.isEmpty())
queryBuilder.append(value);
}
}
}
queryBuilder.deleteCharAt(0);
return queryBuilder.insert(0, '?').toString();
}
private static final long serialVersionUID = 1L;
}
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