社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 8509阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* -|_io,eL;  
**SiteFileFetch.java |p":s3K"Hy  
*/ n_-k <3  
package NetFox; J*]JH{  
import java.io.*; E1Rz<&L  
import java.net.*; ;V)94YT  
0coRar?+b  
d(6&kXK  
public class SiteFileFetch extends Thread { wm/>_  
K${CHKFf  
u %&4[zb  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~,reS:9RZ  
long[] nStartPos; //开始位置 {aWfD XB1  
long[] nEndPos; //结束位置 ~Ec@hz]js  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 tq5o  
long nFileLength; //文件长度 +yIO  
boolean bFirst = true; //是否第一次取文件 xwu,<M v `  
boolean bStop = false; //停止标志 UJGmaE  
File tmpFile; //文件下载的临时信息 a8r+G]Z  
DataOutputStream output; //输出到文件的输出流 StM)lVeF  
pqxBu  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) DP4l %2m0  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0/?=FM >  
{ 'K3%@,O  
siteInfoBean = bean; cUZ^,)8 Z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,:"c"   
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); PoRL35  
if(tmpFile.exists ()) M@O<b-  
{ T eBJ  
bFirst = false; \|Ya*8V  
read_nPos(); =!PUKa3f<  
} Gm'Ch}E  
else 9Q*zf@w  
{ \}NZ] l  
nStartPos = new long[bean.getNSplitter()]; DqlspT  
nEndPos = new long[bean.getNSplitter()]; K2t|d[r  
} [:-o;K\.-a  
-Khb  
wvg>SfV,e  
S:xG:[N@  
} =/F\_/Xw  
o$bD?Zn  
dG'5: ,n/  
public void run() aFwfF^\(|,  
{ fO$~jxR.  
//获得文件长度 cLCzLNyKl  
//分割文件 *saO~.-;4  
//实例FileSplitterFetch ~CL^%\K  
//启动FileSplitterFetch线程 ;gv9J [R  
//等待子线程返回 t&Z:G<;  
try{ qf6}\0   
if(bFirst) +G>;NiP_  
{ Gzu $  
nFileLength = getFileSize(); t!}?nw%$  
if(nFileLength == -1) Y4n; [nHQ(  
{ .%N*g[J  
System.err.println("File Length is not known!"); ppo\cy;  
} oi}\;TG  
else if(nFileLength == -2) `(?x@Y>.Ht  
{ .=-K7.X.)  
System.err.println("File is not access!"); @X*r5hjc  
} F6\r"63  
else 'aW<C>  
{ E>6:59+  
for(int i=0;i<nStartPos.length;i++) 'Z(4Wuwb  
{ =8)q-{p3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); IEJp!P,E  
} IOi6' 1l  
for(int i=0;i<nEndPos.length-1;i++) B|+tK  
{ ;yK:.Vg  
nEndPos = nStartPos[i+1]; #3act )m  
} [XP3  
nEndPos[nEndPos.length-1] = nFileLength; _w>9Z>PR  
} cYMlc wS  
} Q!dNJQpb  
"Hw%@  
Bn_@R`  
//启动子线程 r)SwV!b  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /R44x\nhr  
for(int i=0;i<nStartPos.length;i++) L(!mm  
{ Dx<CO1%z-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :X;AmLf`2u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /IN/SZx  
nStartPos,nEndPos,i); sd~T  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =!%+ sem  
fileSplitterFetch.start(); /K]<7  
} oZ(T`5  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {|J'd+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _GK3]F0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >HXmpu.O  
nEndPos = " + nFileLength); +k4 SN  
// fileSplitterFetch[nPos.length-1].start(); h&6v&%S/L  
*m[ow s  
"?Cx4<nsM  
//等待子线程结束 ?=h{`Ci^ $  
//int count = 0; i@M^9|Gh  
//是否结束while循环 D>Qc/+  
boolean breakWhile = false; ;eRYgC  
"*E%?MG  
YSE6PG   
while(!bStop) 7!E?(3$#"  
{ 9}2E+  
write_nPos(); X4R+Frt8  
Utility.sleep(500); } 6Uw4D61  
breakWhile = true; 'M#'BQQ5  
|VL(#U  
Q+\?gU]  
for(int i=0;i<nStartPos.length;i++) D,rs)  
{ 0FV?By  
if(!fileSplitterFetch.bDownOver) LGm>x  
{ -a[] #v9  
breakWhile = false; &m6x*i-5\f  
break; 75V?K  
} >9.xFiq<  
} WurpHOJt+  
if(breakWhile) ~D)!zQkD  
break; zU9G: jH  
kG7q4jFwP  
C  +%&!Q  
//count++; zU'\r~c  
//if(count>4) &&;ol}W  
// siteStop(); .hxcx>%  
} |E)Es!dr  
'MHbXFM  
xNh#=6__9  
System.err.println("文件下载结束!"); dik+BBu5z  
} xED`8PCfu  
catch(Exception e){e.printStackTrace ();} 8@|rB3J  
} }'KVi=qnHb  
|QvG;{!  
{zc<:^r^  
//获得文件长度 6"Km E}  
public long getFileSize() _ s]=g  
{ heliL/  
int nFileLength = -1; >k?/'R  
try{ ~_TmS9  
URL url = new URL(siteInfoBean.getSSiteURL()); ?N,'1I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 38%xB<Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); E Cx_ [|3{  
Dm j^aFB0|  
F-)lRGw  
int responseCode=httpConnection.getResponseCode(); zOpl#%"  
if(responseCode>=400) L$GhM!c  
{ yVyh'd:Ik  
processErrorCode(responseCode); M[ (mH(j  
return -2; //-2 represent access is error ,HEx9*E/s  
} e4V4%Qw  
AT:T%a:G?  
>69+e+|I  
String sHeader; $Wy7z^ t  
nz|;6?LCLY  
NW`.RGLI<  
for(int i=1;;i++) q9RCXo>Y+1  
{ d]OoJK9&&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u":D{+wC |  
//Utility.log(in.readLine()); ^IxT.g  
sHeader=httpConnection.getHeaderFieldKey(i); B8^tIq  
if(sHeader!=null) ,*2%6t`N?  
{ UlHRA[SCv  
if(sHeader.equals("Content-Length")) Ek+L"7  
{ %($qg-x  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y WSo:)LY  
break; pCz;km  
} "msCiqF{z  
} x=yU }lsV  
else x-0IxWD%  
break; <_ 02)6j  
} J<Wz3}w6  
} aXyu%<@k  
catch(IOException e){e.printStackTrace ();} fv !l{  
catch(Exception e){e.printStackTrace ();} ujZki.x  
,|_ewye  
:z%vNKy1  
Utility.log(nFileLength); &+-ZXN  
>eg&i(C+  
sQ/7Mc  
return nFileLength; n*^g^gp  
} ei;wT  
zYdSg<[^  
~F*pV*  
//保存下载信息(文件指针位置) h'<}N  
private void write_nPos() F_!6C-z  
{ GV1\8OG7  
try{ QeA)@x.p  
output = new DataOutputStream(new FileOutputStream(tmpFile));  K6kPNi  
output.writeInt(nStartPos.length); i+yqsYKO  
for(int i=0;i<nStartPos.length;i++) :b;2iBVB  
{ p#O#M N*  
// output.writeLong(nPos); zh'TR$+\hO  
output.writeLong(fileSplitterFetch.nStartPos);   /I  
output.writeLong(fileSplitterFetch.nEndPos); =y8HOT}8  
} ^>uzMR!q5  
output.close(); pv TV*  
} #lQbMuR  
catch(IOException e){e.printStackTrace ();} }$V]00 X  
catch(Exception e){e.printStackTrace ();} 5j`"@C5;O  
} Phl't~k  
k0?4vA  
tnbaU%;|J  
//读取保存的下载信息(文件指针位置) L1`^~m|  
private void read_nPos() x{u_kepv[k  
{ ?L#C'Lz2+  
try{ t'4hWNR'  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8Uvf9,I'  
int nCount = input.readInt(); ,JT|E~P?8  
nStartPos = new long[nCount]; k+44ud.j  
nEndPos = new long[nCount]; sMli!u  
for(int i=0;i<nStartPos.length;i++) #$%9XD3  
{ ~)D2U:"^xm  
nStartPos = input.readLong(); C81+nR  
nEndPos = input.readLong(); kf0zL3|   
} ?V#%^ 57p  
input.close(); $Vbgfp~U-  
} 673v  
catch(IOException e){e.printStackTrace ();} _%!C;`3Y  
catch(Exception e){e.printStackTrace ();} F8Y D:   
} q|om^:n.  
~R/7J{Sg  
gE JmMh  
private void processErrorCode(int nErrorCode) m:/@DZ  
{ "j3Yu4_ks  
System.err.println("Error Code : " + nErrorCode); |Wj)kr !|  
} F {]:  
ExI?UGT  
bXc7$5(!VB  
//停止文件下载 @g[p>t> *  
public void siteStop() GY<Y,  
{ *-Y77p7u  
bStop = true; P$2J`b[H$  
for(int i=0;i<nStartPos.length;i++) 2Y&z}4'j  
fileSplitterFetch.splitterStop(); 8 +xLi4Pw  
WE4:Jy  
iBxCk^  
} B+ GPTQSTb  
} WW@/q`h  
//负责部分文件的抓取 jfl7L"2  
**FileSplitterFetch.java AZorzQ]s  
*/ u~Q0V J~  
package NetFox; B8Jev\_  
0gHJ%m9s  
w@.E}%bwq  
import java.io.*; ):&A\nb  
import java.net.*; I'BoP  
DyG3|5s1R  
8;p6~&).C~  
public class FileSplitterFetch extends Thread { kX\t0'=]  
J7emoD [  
,Zzh.z::D  
String sURL; //File URL X6!u(plVQ  
long nStartPos; //File Snippet Start Position &pK1S>t  
long nEndPos; //File Snippet End Position <|Bh;;  
int nThreadID; //Thread's ID O9A.WSJ >}  
boolean bDownOver = false; //Downing is over d4[M{LSl  
boolean bStop = false; //Stop identical 0Apdhwk~  
FileAccessI fileAccessI = null; //File Access interface ~y_TT5+ 3  
+uKlg#wqc  
xx nW1`]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `f*?|)  
{ e<l Wel  
this.sURL = sURL; DM!vB+j+,  
this.nStartPos = nStart;  #It{B  
this.nEndPos = nEnd; aT(Pf7 O  
nThreadID = id; '%V ;oJ"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zkI\ji  
} <N=p_m 2T  
C $aiOK-]+  
8~EDmg[  
public void run() /%$'N$@f  
{ `9s5 *;Z  
while(nStartPos < nEndPos && !bStop) rgB`< [:b  
{ fa/ '4  
J@H9nw+Q  
W*u Yb|0  
try{ 9X@y*;w<t  
URL url = new URL(sURL); :bW}*0b-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Tf.KUm  
httpConnection.setRequestProperty("User-Agent","NetFox"); mDvZ 1aj  
String sProperty = "bytes="+nStartPos+"-"; d vkA-9  
httpConnection.setRequestProperty("RANGE",sProperty); QT9(s\u  
Utility.log(sProperty); G#N h)ff  
. CLiv  
=:1f 0QF  
InputStream input = httpConnection.getInputStream(); 3kdTteyy+  
//logResponseHead(httpConnection); j?+FS`a!  
4bhm1Q  
y{s?]hLk  
byte[] b = new byte[1024]; 1*[h$Z&H?  
int nRead; t\CVL?e`  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5(%+8<2  
{ NV9D;g$Y  
nStartPos += fileAccessI.write(b,0,nRead); b@Ik c<  
//if(nThreadID == 1) OlRBv foh8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k^p|H:  
} MH'S,^J  
Mm :6+  
.O3i"X]  
Utility.log("Thread " + nThreadID + " is over!"); pYI`5B4  
bDownOver = true; P@lExF*D1:  
//nPos = fileAccessI.write (b,0,nRead); `T{{wty  
} d&(GIH E&d  
catch(Exception e){e.printStackTrace ();} X{9D fgW  
} (JocnM|U  
} VDx=Tsu-  
TRcY!  
:upi2S_e  
//打印回应的头信息 \Z ] <L  
public void logResponseHead(HttpURLConnection con) O:+#k-?  
{ <3LyNG.  
for(int i=1;;i++) KU"? ZI  
{ vZTX3c:,1  
String header=con.getHeaderFieldKey(i); s)_7*DY  
if(header!=null) ]V<[W,*(5  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :w#Zs)N  
Utility.log(header+" : "+con.getHeaderField(header)); Ii,e=RG>  
else {|^9y]VFu  
break; Um4 }`  
} tUGnD<P  
} s59v* /  
*["9;_KD  
YnNB#x8|  
public void splitterStop() Fm`hFBKW  
{ y)"aQJ>  
bStop = true; Qa5<go{  
} 9 @!Og(l  
LU?X|{z  
 KY!  
} sI@m"A  
ZQD_w#0j  
0X~   
/* TixH Ehw  
**FileAccess.java gkI(B2,/  
*//文件访问(定位,写) mSY;hJi  
package NetFox; S s@\'K3e  
import java.io.*;  PQa {5"  
KX"?3#U#Fm  
fYuJf,I[f  
public class FileAccessI implements Serializable{ j_L 'Ztu3  
hW~,Uqy  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  fv5'Bl  
RandomAccessFile oSavedFile;  w+=>b  
long nPos; rG:IS=  
*%:p01&+  
ZC_b`q<  
public FileAccessI() throws IOException c;xL.  
{ d}EGI  
this("",0); z;zy k  
} ?uc=(J+6  
hvtg_w6K  
6|V713\  
public FileAccessI(String sName,long nPos) throws IOException <?yAIhgN*  
{ eZ[CqUJ&  
oSavedFile = new RandomAccessFile(sName,"rw"); ^cZF#%k  
this.nPos = nPos; 6Hi3h{  
oSavedFile.seek(nPos); jJQ6]ucwa  
} \tye:!a?;@  
I?G m  
H~i+: X=I  
public synchronized int write(byte[] b,int nStart,int nLen) 8v8?D8\=|  
{ 5,:>.LRA  
int n = -1; .</d$FM JE  
try{ c+f~>AaI  
oSavedFile.write(b,nStart,nLen); #|v\UJ:Pf/  
n = nLen; L}h?nWm8  
} ~%qHJ4C  
catch(IOException e) _ "&b%!  
{ azr|Fz/  
e.printStackTrace (); %Nwap~=H;  
} S)iv k x  
3Nd&*QSV  
SpdQ<]  
return n; EFW'D=&h8  
} <ap%+(!I  
i~@e}=  
y1p^ &9 U  
} "diF$Lj  
`J|bGf#  
|#D3~au   
/* WogJ~N,d53  
**SiteInfoBean.java VE+Q Y9(  
*/ :XxsDD  
package NetFox; BKPXXR  
+7U$qEG  
Yz us=  
public class SiteInfoBean { ?[hIv6c  
+;c)GNQ)6:  
H{VVxj  
private String sSiteURL; //Site's URL .}&bE1  
private String sFilePath; //Saved File's Path 'H`aQt+  
private String sFileName; //Saved File's Name e[$=5U~c  
private int nSplitter; //Count of Splited Downloading File 8)s}>:}  
3Wa^:8N  
mDEO$:A  
public SiteInfoBean() Di5eD,N  
{//nSplitter的缺省值为5 dZFf /BXU  
//default value of nSplitter is 5 7;:R\d6iL  
this("","","",5); EdlU}LU  
} 2.{:PM4Z4  
|Gx-c ,{{  
OCnQSkj  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QFY1@2EC  
{  F"FGPk  
sSiteURL= sURL; )cJ9YKKy  
sFilePath = sPath; z lco? Rt  
sFileName = sName; =3$JeNK9  
this.nSplitter = nSpiltter; O68/Hf1W  
,j>A[e&.  
/oKa?iT  
} @d:TAwOI'  
#!wu}nDu  
qPDe;$J)  
public String getSSiteURL() }enm#0Ha  
{ {U?/u93~  
return sSiteURL; hm*1w6 =  
} )D\!#<#h  
X31[  
rV*9=  
public void setSSiteURL(String value) 8fRk8  
{ rJH u~/_Dq  
sSiteURL = value; V*5 ~A [r  
} 3B8\r}L  
]&w8"q  
Vr@I9W;D#  
public String getSFilePath() \B/ +.\  
{ lqh+yX%*  
return sFilePath; \CNv,HUm3  
} J5e  
[vh&o-6  
{Z%4Pg  
public void setSFilePath(String value) }iZO0C  
{ 2L Kpwz?  
sFilePath = value; L}Nc kL  
} P>n}\"z4  
qIIc>By(\"  
g\^7Q  
public String getSFileName() "i0{E!,XL  
{ ,j\1UAa  
return sFileName; =$xxkc.~G  
} @'>h P  
^h #0e:7<  
7%DA0.g  
public void setSFileName(String value) "I+71Ce  
{ }TE4)vXs  
sFileName = value; 7vO3+lT/Y;  
} S bI7<_  
E>>@X^ =  
LgFF+z  
public int getNSplitter() qM%l  
{ {WJ9!pA!lk  
return nSplitter; x.W93e[]H  
} ;U$Fz~rJ  
4+46z|  
1~rZka[s  
public void setNSplitter(int nCount) R@zl?>+  
{ xNDX(_U>\  
nSplitter = nCount; f/+UD-@%m  
} OwRH :l  
} 7HfA{.|m  
ip.aM#  
${fJ]  
/* (Klvctoy  
**Utility.java =, kH(rp2  
*/ 4'EC(NR7N  
package NetFox; kq +`.  
2smQD8t  
Y6<"_  
public class Utility { 93I.Wp_{  
>Z%qkU/  
EhJpJb[Z  
public Utility() vhsHyb  
{ ]1YyP  
v:.`~h/b  
MYI*0o;  
} j !m42  
>Vp #   
//线程睡眠 A_nu:K-  
public static void sleep(int nSecond) jiAKV0lX W  
{ Ek#?B6s  
try{ Qmbl_#  
Thread.sleep(nSecond); hf#[Vns  
} LYM(eK5V  
catch(Exception e) &.D#OnRh9  
{ ]CL t Km  
e.printStackTrace (); XNZW J  
} s,~)5nL  
} >2kjd  
Owt|vceT  
//日志 f\c m84  
public static void log(String sMsg) v>ygr8+C,  
{ [&_c.ti  
System.err.println(sMsg); FH Hi/yh  
} (c3%rM m]  
>U4hsr05  
#0*OkZMt  
public static void log(int sMsg) Dq$co1eT  
{ R>|)-"b( `  
System.err.println(sMsg); 6,J:sm\  
} $<c;xDO&t  
} 0xZX%2E  
7R4xJ H  
-`d9dJ dB  
/* `-,yJ  
**TestMethod.java 7|vB\[s  
*/ ;`CNe$y   
package NetFox; T1Gy_ G/  
;Nfd  
fG{ 9doUD  
public class TestMethod { d]bM,`K* 6  
H6fR6Kr4j  
XMJEIG  
public TestMethod() sD_"  
{ ///xx/weblogic60b2_win.exe OsSGVk #Qh  
try{ gJkvH[hDY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X.YMb .\<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *d%U]Hby,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); v8PH(d2{@  
fileFetch.start(); t93iU?Z  
} wfE%` 1  
catch(Exception e){e.printStackTrace ();} Z{#;my*X|  
B%~D`[~?  
\@%sX24D  
} ~-dL #;  
sPKyg  
moe5H  
public static void main(String[] args) B^{87YR  
{ +0)zB;~7  
new TestMethod(); F~qiNV  
} (";{@a %  
} d7O\p(M1  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五