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android 中volley二次封装并实现网络请求缓存
android目前很多同学使用volley请求网络数据，但是volley没有对请求过得数据进行缓存，因此需要我们自己手动缓存。 一下就是我的一种思路，仅供参考
具体使用方法为：
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hashmap<string,string> params = new hashmap<>();
params.put("id", "1");
params.put("user", "mcoy");
new networkhelper(getactivity()).jacksonmethodrequest
("method_id", params, new typereference<returntemple<firstcategories>>(){}, handler, msgid);
networkhelper---对volley的封装，首先调用cachemanager.get(methodname, params);方法获取缓存中的数据，如果数据为null，
则继续发送网络请求。
/**
* @version v1.0 网络请求帮助类
* @author: mcoy
*/
public final class networkhelper {
private networkmanager networkutils;
public networkhelper(context context){
networkutils = new networkmanager(context);
}
public static final string common_error_msg = "连接超时，请稍后重试";
public static final int common_error_code = 2;
/**
* 使用jackson请求的方法
* @param methodname
* @param params
* @param handler
* @param msgid
*/
public void jacksonmethodrequest(final string methodname,final hashmap<string,string> params,typereference javatype, final handler handler,final int msgid){
responselistener listener = new responselistener(){
@override
public void onresponse(object response, boolean iscache) {
printlog.log(response.tostring());
if (iscache){
cachemanager.put(methodname, params, response);
}
if (handler != null) {
message message = handler.obtainmessage();
message.what = msgid;
message.obj = response;
handler.sendmessage(message);
}
}
};
object respone = cachemanager.get(methodname, params);
if(respone != null){
listener.onresponse(respone,false);
return;
}
hashmap<string,string> allparams = config.setsign(true);
allparams.putall(params);
response.errorlistener errorlistener = new response.errorlistener() {
@override
public void onerrorresponse(volleyerror error) {
error.printstacktrace();
if (handler != null) {
message message = handler.obtainmessage();
message.what = msgid;
message.obj = common_error_msg;
handler.sendmessage(message);
}
}
};
networkutils.jacksonrequest(geturl(methodname), allparams,javatype, listener, errorlistener);
}
/**
* url直接请求
* @param url
* @param params
* @param handler
* @param msgid
*/
public void urlrequest(string url,hashmap<string,string> params,jsonparser jsonparser,final handler handler,final int msgid){
request(url, true, params, jsonparser, handler, msgid);
}
/**
* 通过方法请求
* @param methodname 方法名
* @param params 请求参数
* @param jsonparser json解析器
* @param handler 回调通知
* @param msgid 通知的id
*/
public void methodrequest(string methodname, final hashmap<string,string> params,final jsonparser jsonparser,final handler handler,final int msgid){
request(geturl(methodname),true,params,jsonparser,handler,msgid);
}
/**
* 通过方法请求
* @param methodname 方法名
* @param params 请求参数
* @param jsonparser json解析器
* @param handler 回调通知
* @param msgid 通知的id
*/
public void methodrequest(string methodname, boolean islogin,final hashmap<string,string> params,final jsonparser jsonparser,final handler handler,final int msgid){
request(geturl(methodname),islogin,params,jsonparser,handler,msgid);
}
private void request(final string url, boolean islogin,final hashmap<string,string> params,final jsonparser jsonparser,final handler handler,final int msgid){
final hashmap<string,string> allparams = config.setsign(islogin);
allparams.putall(params);
response.listener listener = new response.listener<string>() {
@override
public void onresponse(string response) {
/**
* 有些请求默认是没有parser传过来的，出参只求string，譬如联合登录等
* 所以加了一个else if
*/
object result;
printlog.log(response);
if (jsonparser != null ) {
jsonparser.json2obj(response);
jsonparser.temple.description = jsonparser.temple.getresultdescription();
result = jsonparser.temple;
} else {
returntemple temple = new returntemple();
temple.issuccessful = false;
temple.description = common_error_msg;
temple.result = -100;
result = temple;
}
if (handler != null) {
message message = handler.obtainmessage();
message.what = msgid;
message.obj = result;
handler.sendmessage(message);
}
}
};
response.errorlistener errorlistener = new response.errorlistener() {
@override
public void onerrorresponse(volleyerror error) {
object result;
if (jsonparser != null) {
returntemple temple = new returntemple();
temple.issuccessful = false;
temple.description = common_error_msg;
temple.result = common_error_code;
result = temple;
} else {
result = common_error_msg;
}
if (handler != null) {
message message = handler.obtainmessage();
message.what = msgid;
message.obj = result;
handler.sendmessage(message);
}
}
};
networkutils.request(url, allparams, listener, errorlistener);
}
/**
* 根据访求名拼装请求的url
* @param methodname
* @return
*/
private string geturl(string methodname){
string url = config.geturl();
if (!stringutil.isnullorempty(methodname)) {
url = url + "?method=" + methodname;
}
return url;
}
}
cachemanager---将针对某一method所请求的数据缓存到本地文件当中，主要是将cacherule写到本地文件当中
/**
* @version v1.0 <缓存管理>
* @author: mcoy
*/
public final class cachemanager {
/**
* 一个方法对应的多个key，比如分类都是同一个方法，但是请求会不一样，可能都要缓存
*/
private static hashmap<string, arraylist<string>> methodkeys;
private static final string keyfilename = "keys.pro";
/**
* 读取缓存的key
*/
public static void readcachekey() {
methodkeys = (hashmap<string, arraylist<string>>) readobject(keyfilename);
if (methodkeys == null) {
methodkeys = new hashmap<string, arraylist<string>>();
}
}
/**
* 保存缓存
*/
public static void put(string method, hashmap<string, string> params, object object) {
long expiretime = cacheconfig.getexpiretime(method);
if (expiretime <= 0 || methodkeys == null) {//有效时间小于0，则不需要缓存
return;
}
string key = createkey(method, params);
if (methodkeys.containskey(method)) {
arraylist<string> keys = methodkeys.get(method);
keys.add(key);
} else {
arraylist<string> keys = new arraylist<>();
keys.add(key);
methodkeys.put(method, keys);
}
writeobject(methodkeys, keyfilename);
string filename = key + ".pro";
cacherule cacherule = new cacherule(expiretime, object);
logmodel.log(" put " + method + " " + key + " " + cacherule);
writeobject(cacherule, filename);
}
public static object get(string method, hashmap<string, string> params) {
long expiretime = cacheconfig.getexpiretime(method);
if (expiretime <= 0 || methodkeys == null || !methodkeys.containskey(method)) {//有效时间小于0，则不需要缓存
return null;
}
arraylist<string> keys = methodkeys.get(method);
// string savekey = keys.get(method);
string key = createkey(method, params);
string filename = key + ".pro";
// logmodel.log("get"+method+" "+(savekey.equals(key))+" path:"+filename);
cacherule cacherule = null;
try {
if (keys.contains(key)) {
cacherule = (cacherule) readobject(filename);
}
} catch (exception e) {
e.printstacktrace();
}
logmodel.log("get :" + method + " " + key + " " + cacherule);
if (cacherule != null && cacherule.isexpire()) {
return cacherule.getdata();
} else {
return null;
}
}
public static void main(string[] args) {
string method = "category.getcategory";
hashmap<string, string> params = new hashmap<>();
params.put("categoryid", "-3");
system.out.println(createkey(method, params));
system.out.println(cacherule.getcurrenttime());
}
/**
* 生成key
*
* @param method 请求的方法名
* @param params 私有参数(除公共参数以外的参数)
* @return
*/
private static string createkey(string method, hashmap<string, string> params) {
try {
messagedigest digest = messagedigest.getinstance("md5");
digest.digest(method.getbytes("utf-8"));
stringbuilder builder = new stringbuilder(method);
if (params != null && params.size() > 0) {
iterator<map.entry<string, string>> iterator = params.entryset().iterator();
while (iterator.hasnext()) {
map.entry<string, string> entry = iterator.next();
builder.append(entry.getkey()).append("=").append(entry.getvalue());
}
}
byte[] temparray = digest.digest(builder.tostring().getbytes("utf-8"));
stringbuffer keys = new stringbuffer();
for (byte b : temparray) {
// 与运算
int number = b & 0xff;// 加盐
string str = integer.tohexstring(number);
// system.out.println(str);
if (str.length() == 1) {
keys.append("0");
}
keys.append(str);
}
return keys.tostring().touppercase();
} catch (exception e) {
e.printstacktrace();
}
return method.touppercase();
}
/**
* 将对象写到文件中
*
* @param object
* @param filename
*/
private static void writeobject(object object, string filename) {
try {
objectoutputstream oo = new objectoutputstream(new fileoutputstream(new file(cacheconfig.getcachepath() + filename)));
oo.writeobject(object);
oo.close();
} catch (ioexception e) {
e.printstacktrace();
}
}
/**
* 读取对象
*
* @param filename
* @return
*/
private static object readobject(string filename) {
object result = null;
try {
file file = new file(cacheconfig.getcachepath() + filename);
if (file.exists()) {
objectinputstream oi = new objectinputstream(new fileinputstream(file));
result = oi.readobject();
oi.close();
}
} catch (exception e) {
e.printstacktrace();
}
return result;
}
}
cacheconfig---初始化哪些方法需要做缓存处理，以及缓存的有效时间
/**
* @version v1.0 <设置哪些类数据需要缓存>
* @author: mcoy
*/
public final class cacheconfig {
/**方法对应的缓存有效时间，时间是毫秒*/
private static hashmap<string,long> methodexpiretimes = new hashmap<string, long>();
private static string cachepath = null;
static {
methodexpiretimes.put(constmethod.get_category_list,30 * 60 * 1000l);
methodexpiretimes.put(constmethod.get_new_category_list,30 * 60 * 1000l);
}
/**
* 初始化缓存路径
* @param context
*/
public static void init(context context){
cachepath = context.getfilesdir().getpath()+ file.separator+"cache"+file.separator;
file file = new file(cachepath);
if(!file.exists()){
file.mkdirs();
}
cachemanager.readcachekey();
}
/**缓存路径*/
public static string getcachepath() {
return cachepath;
}
/**
* 获取有方法对应的有效时间，如果方法没有添加缓存或者缓存时间小于0，则不添加缓存
* @param method
* @return
*/
public static long getexpiretime(string method){
if(methodexpiretimes.containskey(method)){
return methodexpiretimes.get(method);
}else {
return -1;
}
}
}
cacherule---主要有两个参数，expiretime需要缓存的时间， data需要缓存的数据
public class cacherule implements serializable{
/** 有效时间 */
public long expiretime;
/** 缓存时间*/
public long cachetime;
/** 缓存数据 */
private object data;
public cacherule(long expiretime,object data){
cachetime = getcurrenttime();
this.expiretime = expiretime;
this.data = data;
}
public object getdata() {
return data;
}
public void setdata(object data) {
this.data = data;
}
@override
public int hashcode() {
return beantools.createhashcode(expiretime, cachetime, data);
}
@override
public string tostring() {
stringbuilder builder = new stringbuilder();
builder.append("expiretime:").append(expiretime).append(" cachetime:").append(cachetime)
.append(" curtime:").append(getcurrenttime())
.append(" isexpire:").append(isexpire()).append(" data:").append(data==null?"null":data.tostring());
return builder.tostring();
}
/**
* 数据是否有效
* @return
*/
public boolean isexpire(){
long curtime = getcurrenttime();
return curtime>(expiretime+cachetime)?false:true;
}
/**
* 获取当前时间
* @return
*/
public static long getcurrenttime(){
// if (build.version_codes.jelly_bean_mr1 <= build.version.sdk_int) {
// return systemclock.elapsedrealtimenanos();
// } else {
return system.currenttimemillis();
// }
}
}
networkmanager---往requestqueue中添加jacksonrequest请求，然后volley会去请求数据
/**
* 网络请求的工具类
*/
public final class networkmanager {
private requestqueue requestqueue ;
public networkmanager(context context){
requestqueue = volley.newrequestqueue(context);
}
/**
* 使用jackson解析请求的方法
* @param url
* @param params
* @param javatype 成功时返回的java类型
* @param listener
* @param errorlistener
*/
public void jacksonrequest(final string url,final hashmap<string,string> params,typereference javatype, responselistener listener, response.errorlistener errorlistener){
jacksonrequest jacksonrequest = new jacksonrequest(url,javatype,params,listener,errorlistener);
requestqueue.add(jacksonrequest);
}
/**
* 普通的网络请求，返回的json
* @param url
* @param params
* @param listener
* @param errorlistener
*/
public void request(final string url,final hashmap<string,string> params,response.listener listener,response.errorlistener errorlistener){
stringrequest stringrequest = new stringrequest(request.method.post,url,listener,errorlistener){
@override
protected map<string, string> getparams() throws authfailureerror {
if (printlog.debug) {
iterator<map.entry<string,string>> iterator = params.entryset().iterator();
stringbuilder builder = new stringbuilder(url+" ");
while (iterator.hasnext()){
map.entry<string,string> entry = iterator.next();
builder.append(entry.getkey()+":"+entry.getvalue()).append("; ");
}
printlog.log(builder.tostring());
}
return params;
}
};
requestqueue.add(stringrequest);
}
}
jacksonrequest---继承request，重写deliverresponse方法，并调用responselistener的onresponse方法，并通过cachemanager.put(methodname, params, response);将获取的response缓存到cachemanager中。这一步很重要，调用我们自己的listener，而不是volley提供给我们的response.listener
/**
* created by mcoy
*/
public class jacksonrequest extends request {
private final hashmap<string,string> params;
private final responselistener listener;
private final objectmapper mapper;
private final typereference javatype;
public jacksonrequest(string url,typereference javatype,hashmap<string,string> params,responselistener listener,response.errorlistener errorlistener){
super(method.post,url,errorlistener);
mapper = new objectmapper();
mapper.configure(jsonparser.feature.allow_single_quotes,true);
mapper.configure(deserializationfeature.fail_on_unknown_properties, false);
this.params = params;
this.listener = listener;
this.javatype = javatype;
}
@override
protected map<string, string> getparams() throws authfailureerror {
return params;
}
@override
protected response parsenetworkresponse(networkresponse response) {
string json;
try {
json = new string(response.data, httpheaderparser.parsecharset(response.headers));
printlog.log("返回的json:" + json);
return response.success(mapper.readvalue(json,javatype), httpheaderparser.parsecacheheaders(response));
}catch (unsupportedencodingexception e){
json = new string(response.data);
printlog.log("json:"+json);
try {
return response.success(mapper.readvalue(json,javatype),httpheaderparser.parsecacheheaders(response));
} catch (ioexception e1) {
return response.error(new parseerror(e));
}
} catch (jsonparseexception e) {
printlog.log(e.tostring());
return response.error(new parseerror(e));
} catch (jsonmappingexception e) {printlog.log(e.tostring());
return response.error(new parseerror(e));
} catch (ioexception e) {printlog.log(e.tostring());
return response.error(new parseerror(e));
}
}
@override
protected void deliverresponse(object response) {
listener.onresponse(response,true);
}
}
responselistener---自定义的一个listener接口， 在发送请求时，需要将其实现。其中才参数中比volley的提供的listener过了一个iscache的boolean值，根据此值来决定是否要缓存。
/**
* @version v1.0 <描述当前版本功能>
* @author: mcoy
*/
public interface responselistener<t> {
public void onresponse(t response, boolean iscache);
}
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