com.devops4j.embedded.httpserver.Headers Maven / Gradle / Ivy
package com.devops4j.embedded.httpserver;
import java.util.*;
/**
* HTTP request and response headers are represented by this class which implements
* the interface
* {@link java.util.Map}{@literal <}{@link java.lang.String}, {@link java.util.List}
* {@literal <}{@link java.lang.String}{@literal >>}.
* The keys are case-insensitive Strings representing the header names and
* the value associated with each key is
* a {@link List}{@literal <}{@link String}{@literal >} with one
* element for each occurrence of the header name in the request or response.
*
* For example, if a response header instance contains
* one key "HeaderName" with two values "value1 and value2"
* then this object is output as two header lines:
*
* HeaderName: value1
* HeaderName: value2
*
*
* All the normal {@link java.util.Map} methods are provided, but the following
* additional convenience methods are most likely to be used:
*
* - {@link #getFirst(String)} returns a single valued header or the first value of
* a multi-valued header.
* - {@link #add(String,String)} adds the given header value to the list for the given key
* - {@link #set(String,String)} sets the given header field to the single value given
* overwriting any existing values in the value list.
*
* All methods in this class accept null values for keys and values. However, null
* keys will never will be present in HTTP request headers, and will not be output/sent in response headers.
* Null values can be represented as either a null entry for the key (i.e. the list is null) or
* where the key has a list, but one (or more) of the list's values is null. Null values are output
* as a header line containing the key but no associated value.
* @since 1.6
*/
public class Headers implements Map> {
HashMap> map;
public Headers () {map = new HashMap(32);}
/* Normalize the key by converting to following form.
* First char upper case, rest lower case.
* key is presumed to be ASCII
*/
private String normalize (String key) {
if (key == null) {
return null;
}
int len = key.length();
if (len == 0) {
return key;
}
char[] b = key.toCharArray();
if (b[0] >= 'a' && b[0] <= 'z') {
b[0] = (char)(b[0] - ('a' - 'A'));
}
for (int i=1; i= 'A' && b[i] <= 'Z') {
b[i] = (char) (b[i] + ('a' - 'A'));
}
}
return new String(b);
}
public int size() {return map.size();}
public boolean isEmpty() {return map.isEmpty();}
public boolean containsKey(Object key) {
if (key == null) {
return false;
}
if (!(key instanceof String)) {
return false;
}
return map.containsKey (normalize((String)key));
}
public boolean containsValue(Object value) {
return map.containsValue(value);
}
public List get(Object key) {
return map.get(normalize((String)key));
}
/**
* returns the first value from the List of String values
* for the given key (if at least one exists).
* @param key the key to search for
* @return the first string value associated with the key
*/
public String getFirst (String key) {
List l = map.get(normalize(key));
if (l == null) {
return null;
}
return l.get(0);
}
public List put(String key, List value) {
return map.put (normalize(key), value);
}
/**
* adds the given value to the list of headers
* for the given key. If the mapping does not
* already exist, then it is created
* @param key the header name
* @param value the header value to add to the header
*/
public void add (String key, String value) {
String k = normalize(key);
List l = map.get(k);
if (l == null) {
l = new LinkedList();
map.put(k,l);
}
l.add (value);
}
/**
* sets the given value as the sole header value
* for the given key. If the mapping does not
* already exist, then it is created
* @param key the header name
* @param value the header value to set.
*/
public void set (String key, String value) {
LinkedList l = new LinkedList();
l.add (value);
put (key, l);
}
public List remove(Object key) {
return map.remove(normalize((String)key));
}
public void putAll(Map> t) {
map.putAll (t);
}
public void clear() {map.clear();}
public Set keySet() {return map.keySet();}
public Collection> values() {return map.values();}
public Set>> entrySet() {
return map.entrySet();
}
public boolean equals(Object o) {return map.equals(o);}
public int hashCode() {return map.hashCode();}
}