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
  • 10585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
/* #QQ\xj  
**SiteFileFetch.java ..3TB=Z#  
*/ #IA[erf:  
package NetFox; CtV$lXxup  
import java.io.*; ^.&uYF&  
import java.net.*; ++F #Z(p  
7m{ 'V`F  
2[LT!TT  
public class SiteFileFetch extends Thread { dY68wW>d|  
"3LOL/7f  
kdman nM  
SiteInfoBean siteInfoBean = null; //文件信息Bean v2G_p |+O  
long[] nStartPos; //开始位置 ]T}G-  
long[] nEndPos; //结束位置 9 }iEEI  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 mm'n#%\G  
long nFileLength; //文件长度 bv5,Yk  
boolean bFirst = true; //是否第一次取文件 ;hJTJMA6/6  
boolean bStop = false; //停止标志 /$'tO3  
File tmpFile; //文件下载的临时信息 1Z6<W~,1OM  
DataOutputStream output; //输出到文件的输出流 "'p:M,:  
FF6[qSV  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |8 c3%jve  
public SiteFileFetch(SiteInfoBean bean) throws IOException o*eU0  
{ }H!c9Y  
siteInfoBean = bean; 4K[E3aA  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a[]=*(AZI  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <s2IC_f<+  
if(tmpFile.exists ()) Bjq1za  
{ +^Eruv+F  
bFirst = false; ?P ,z^  
read_nPos(); ~dC)EG  
} )7Gm<r  
else 3_~V(a  
{ s[NkPh9&  
nStartPos = new long[bean.getNSplitter()]; kjfZ*V=-  
nEndPos = new long[bean.getNSplitter()]; 2aX|E4F  
} Jm0P~E[n  
m{x[q  
RZ:Yu  
Bab`wfUve  
} WW\u}z.QJ  
=LDzZ:' X  
g2JNa?z  
public void run() [U]U *x  
{ \Pi\c~)Pr  
//获得文件长度 /qed_w.p  
//分割文件 57*z0<  
//实例FileSplitterFetch #Gx%PQ`  
//启动FileSplitterFetch线程 wUW^ O  
//等待子线程返回 rS\j9@=Y4  
try{ fPZt*A__  
if(bFirst) $[T^ S  
{ ' 7+x,TszI  
nFileLength = getFileSize(); O $'# 8  
if(nFileLength == -1) 9cp-Rw<tI  
{ vP`Sz}FU  
System.err.println("File Length is not known!"); a$yAF4HR<  
} 5,})x]'x  
else if(nFileLength == -2) Fm_^7|  
{ t>N~PXr  
System.err.println("File is not access!"); +w[vYKSZm  
} 7"@^JxYN  
else ^[,Q2MHCT(  
{ d&4 ve Lu  
for(int i=0;i<nStartPos.length;i++) M(KsLu1   
{ ExeD3Zj  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =,$*-<p=3  
} Wf/r@/ q  
for(int i=0;i<nEndPos.length-1;i++) f_Ma~'3   
{ dKTyh:_{  
nEndPos = nStartPos[i+1]; 3p6QJuSB  
} :m]~o3KRy  
nEndPos[nEndPos.length-1] = nFileLength; f6vhW66:?x  
} njtz,qt_;G  
} 2 -72 8  
ukpbx;O:hc  
[Ul"I-K  
//启动子线程 "s]r"(MX  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T\I}s"d  
for(int i=0;i<nStartPos.length;i++) XLb lVi@  
{ g>-pC a  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3O7]~5 j1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qq.M]?Z  
nStartPos,nEndPos,i); S[J eW  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3u#bx1  
fileSplitterFetch.start(); U$v|c%6  
} CuC1s>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  a?S5 =  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^MIF+/bQ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N;4bEcWjp  
nEndPos = " + nFileLength); nF>41 K  
// fileSplitterFetch[nPos.length-1].start(); =!)Ye:\Q  
)UbPG`x8  
TwlX'iI_;  
//等待子线程结束 iGB1f*K%x  
//int count = 0; H xs'VK*  
//是否结束while循环 U;`C%vHff  
boolean breakWhile = false; J|,Uu^7`  
-{`8Av5)E%  
\~ m\pf?  
while(!bStop) 5{Q5?M]  
{ N(uHy@  
write_nPos(); F] e` -;  
Utility.sleep(500); R d'P\  
breakWhile = true; Gu+9R>  
:No`+X[Kq  
2(LF @xb  
for(int i=0;i<nStartPos.length;i++) K+MSjQS"  
{ 7irpD7P>  
if(!fileSplitterFetch.bDownOver) -fpe  
{ H3-(.l[!b)  
breakWhile = false; ^Ej$o@PH  
break; E|{(O  
} %"-bG'Yc  
} 9<n2-l|)  
if(breakWhile) Ln:6@Ok)5%  
break; [NE|ZL~  
A12EUr5$  
5.ibH  
//count++; F t/yPv  
//if(count>4) XSk*w'xO  
// siteStop(); 2[|52+zhc  
} =mR~\R( I  
z]_2lx2e  
L$L/5/  
System.err.println("文件下载结束!"); yPY}b_W  
} `eZzYe(N  
catch(Exception e){e.printStackTrace ();} Y TpiOPf  
} QN47+)cVt"  
Vu.VH([b]Q  
&O +?#3  
//获得文件长度 /tm2b<G  
public long getFileSize() n(I,pF  
{ "DaE(S&  
int nFileLength = -1; 4Vtu g>  
try{ 1lo. X_  
URL url = new URL(siteInfoBean.getSSiteURL()); _%g L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P:D;w2'Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); aVB/Co M9  
$UNC0 (4  
i;Dj16h  
int responseCode=httpConnection.getResponseCode(); Q g~cYwX  
if(responseCode>=400) |RjAp.pm  
{ zh{,.c  
processErrorCode(responseCode); {wy{L-X  
return -2; //-2 represent access is error >?<S(  
} Tp46K\}Uf  
QB uX#bDV  
Emy=q5ryl  
String sHeader; b?{MXJ|  
|L/EH~| O  
cwuzi;f  
for(int i=1;;i++) E1r-$gf_  
{ vA3wn><  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dx@|M{jz'  
//Utility.log(in.readLine()); Mj&G5R~_  
sHeader=httpConnection.getHeaderFieldKey(i); LBxmozT  
if(sHeader!=null) Vv54;Js9  
{ @An}  
if(sHeader.equals("Content-Length")) 0=0,ix7?#  
{ \sMe2OL#z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l1bkhA b  
break; Y~ xo=v(  
} lArKfs/   
} X[<%T}s#  
else ho-#Xbq#g  
break; /KLkrW  
} z$gtGrU  
} kmUL^vF  
catch(IOException e){e.printStackTrace ();} 3CzF@t;5  
catch(Exception e){e.printStackTrace ();} 8`<e\g7-  
>.M>,m\  
X=+|(A,BdY  
Utility.log(nFileLength); w73?E#8  
fB80&G9  
IM% ,A5u  
return nFileLength; 5U-SIG*  
} 6r|=^3{  
W#)X@TlE  
8.,d`~  
//保存下载信息(文件指针位置) P_4E<"eK  
private void write_nPos() @Jx1n Q^  
{ H;R~d%!b  
try{ 6hMKAk  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #f [}a  
output.writeInt(nStartPos.length); Oa2\\I  
for(int i=0;i<nStartPos.length;i++) v,C~5J3h)  
{ ^@3,/dH1 t  
// output.writeLong(nPos); 5(gWK{R)*  
output.writeLong(fileSplitterFetch.nStartPos); br^ A<@,d  
output.writeLong(fileSplitterFetch.nEndPos); &~Pk*A_:  
} ,Nt^$2DZW  
output.close(); t~7OtPF  
} (dfC}x(3h  
catch(IOException e){e.printStackTrace ();} TjDtNE  
catch(Exception e){e.printStackTrace ();} 'hE'h?-7  
} IyI0|&r2A  
q{&\nCy  
0-~s0R89A  
//读取保存的下载信息(文件指针位置) []v$QR&u#v  
private void read_nPos() )s,LFIy<A  
{ Gx %=&O  
try{ =z;]FauR!  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RL:B.Lv/W  
int nCount = input.readInt(); O6/:J#X%  
nStartPos = new long[nCount]; $ay!'MK0d  
nEndPos = new long[nCount]; oYdE s&qq  
for(int i=0;i<nStartPos.length;i++) &?1O D5  
{ Lb)rloca  
nStartPos = input.readLong(); 6DU~6c=)  
nEndPos = input.readLong(); tKS[  
} ,-hbwd~M  
input.close(); n$`+03a  
} | p!($  
catch(IOException e){e.printStackTrace ();} :hT.L3n,  
catch(Exception e){e.printStackTrace ();} e!PB3I  
} %ufh  
NT0n [o^  
]J[d8S5  
private void processErrorCode(int nErrorCode) S)g:+P  
{ 81"` B2  
System.err.println("Error Code : " + nErrorCode); Pz34a@%"  
} _Dd>e=v  
#|4G,!  
=\_gT=tZ  
//停止文件下载 jz`3xFy *]  
public void siteStop() 7Q]c=i cg  
{ gyMHC{l/B  
bStop = true; iGSA$U P|  
for(int i=0;i<nStartPos.length;i++) V3# ms0  
fileSplitterFetch.splitterStop(); P3`$4p?  
MT"&|Og  
)=sbrCl,C/  
} (8aj`> y  
} J^`5L7CO  
//负责部分文件的抓取 -uWV( ,|  
**FileSplitterFetch.java q\}+]|nGs  
*/ ,cL;,YN  
package NetFox; 5@%.wb4  
h}! 9?:E  
x&*f5Y9hCi  
import java.io.*; ;}iB9 Tl  
import java.net.*; ff5 gE'  
z~X/.>  
F@k}p-e~  
public class FileSplitterFetch extends Thread { 9Q^cE\j  
5L:-Xr{  
jQzl!f1c3  
String sURL; //File URL 'UUj(1 f  
long nStartPos; //File Snippet Start Position f+Acs*. GQ  
long nEndPos; //File Snippet End Position WB?HY?[r  
int nThreadID; //Thread's ID :IU7dpwDl  
boolean bDownOver = false; //Downing is over #gqh0 2 7  
boolean bStop = false; //Stop identical m0 As t<u  
FileAccessI fileAccessI = null; //File Access interface ;xe.0j0h  
BO#tn{(#  
SF&2a(~s  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5e$1KN`  
{ vjS=ZinN"  
this.sURL = sURL; 4MS#`E7LrC  
this.nStartPos = nStart; Jn^b}bk t  
this.nEndPos = nEnd; Hc =QSP  
nThreadID = id; ghWWJx9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %2T i Rb  
} *s*Y uY%y  
')!X1A{  
Oo@o$\+v  
public void run() ^e_LnJ+  
{ chKK9SC+|  
while(nStartPos < nEndPos && !bStop) n'v\2(&uYN  
{ -z~!%4 a  
Ac|\~w[\  
cd1G.10  
try{ R8k4?_W?T  
URL url = new URL(sURL); R__:~ uv,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _0v+'&bz  
httpConnection.setRequestProperty("User-Agent","NetFox"); sde>LZet/  
String sProperty = "bytes="+nStartPos+"-"; }VZExqm)  
httpConnection.setRequestProperty("RANGE",sProperty); V-}}?c1 F  
Utility.log(sProperty); <M@-|K"Eb  
ey=KAt  
N"G aQ  
InputStream input = httpConnection.getInputStream(); q50F!yHC-  
//logResponseHead(httpConnection); /3,Lp-kp  
>P SO]%mE  
q:/df]Ntt  
byte[] b = new byte[1024]; 4lB??`UN  
int nRead; 8rH6L:]S  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8{!d'Pks  
{ 3{$7tck,  
nStartPos += fileAccessI.write(b,0,nRead); -p&u=  
//if(nThreadID == 1) L)bMO8JH~m  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A}SGw.3  
} 0o=HOCL\  
^" X.aksA  
\jtA8o%n  
Utility.log("Thread " + nThreadID + " is over!"); 0SQr%:zG  
bDownOver = true; Fs(PVN  
//nPos = fileAccessI.write (b,0,nRead); Z-Qp9G'   
} 2Qp}f^  
catch(Exception e){e.printStackTrace ();} Mg.%&vH\  
} N! 7}B  
} :rUMmO-  
B= {_}f  
Q2VF+g,  
//打印回应的头信息 m4 (p MrJ  
public void logResponseHead(HttpURLConnection con) n?.;*:  
{ W~/d2_|/  
for(int i=1;;i++) CpO_p%P  
{ aX^T[  
String header=con.getHeaderFieldKey(i); Zk%@GOu\  
if(header!=null) x/umwT,ov  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `y3'v]  
Utility.log(header+" : "+con.getHeaderField(header)); yx5e  
else Sl G v  
break; E7fQ9]  
} I_<XL<  
} MqnUym  
#y83tNev  
G kjfDY:  
public void splitterStop() 172G  
{ _-TplGSO=c  
bStop = true; $+'H000x  
} I "AjYv4R  
^m w]u"5\  
x,,y}_YX  
} Io]FDPN  
V.P<>~W  
TlS? S+  
/* B-Jd|UE`u  
**FileAccess.java \b"rf697 ,  
*//文件访问(定位,写) E$)|Kv^  
package NetFox; WR)=VE   
import java.io.*; ^)Hf%  
&J6`Q<U!  
>ou= }/<  
public class FileAccessI implements Serializable{ Sf*)Z3f  
KdR4<qVV}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h=7q;-@7  
RandomAccessFile oSavedFile; b_31 \  
long nPos; vFVUdxPOw  
zFq%[ X  
N-M.O:p  
public FileAccessI() throws IOException Tn}`VW~  
{ 6h;(b2p{  
this("",0); 8)X9abC  
} DXiA4ihr=  
%bDxvaftT  
MxsLrWxm  
public FileAccessI(String sName,long nPos) throws IOException (F4e}hr&  
{ xnY?<?J"!  
oSavedFile = new RandomAccessFile(sName,"rw"); $Z@*!B^  
this.nPos = nPos; ?G,4N<]Nu  
oSavedFile.seek(nPos); >!=@TK(~  
} G]'ah1W  
^c\O , *:  
$+*nb4  
public synchronized int write(byte[] b,int nStart,int nLen) |Kd#pYt%O  
{ f$o^Xu  
int n = -1; Sa= tiOv  
try{ N(&{~*YE  
oSavedFile.write(b,nStart,nLen); f^$,;  
n = nLen; Hf`i~6  
} GJ,&$@8)  
catch(IOException e) 3f7zW3F  
{ J/je/PC  
e.printStackTrace (); &h334N|4{  
} h Qn?qJy%W  
<~ smBd  
p;+O/'/j  
return n; N[I@}j  
} XN df  
7rjl-FUA~  
:; +!ID_  
} \;{ ]YX  
* 65/gG8>  
d51lTGH7Z  
/* <Vhd4c  
**SiteInfoBean.java G^c,i5}w  
*/ v Y[s#*+  
package NetFox; jrib"Bh3,  
U#3N90,N=  
9-42A7g^C  
public class SiteInfoBean { nGF +a[Z  
}_D.Hy5  
g*V.u]U!i  
private String sSiteURL; //Site's URL (T%F^s5D  
private String sFilePath; //Saved File's Path pR S!  
private String sFileName; //Saved File's Name o :d7IL  
private int nSplitter; //Count of Splited Downloading File a"vzC$Hxd  
v)5;~.+%  
"V|Rq]_+%  
public SiteInfoBean() V\L;EHtc$  
{//nSplitter的缺省值为5 is<:}z  
//default value of nSplitter is 5 .vu7$~7  
this("","","",5); \o>-L\`O  
} C]ss'  
b"I#\;Ym  
2 2v"?*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V!Wy[u  
{ UleT9 [M  
sSiteURL= sURL; !nBbt?*  
sFilePath = sPath; *qpu!z2m||  
sFileName = sName; LqWiw24#  
this.nSplitter = nSpiltter; Af|h*V4Xu  
-<g9 ) CV5  
(p{X.X+  
} )d3 09O  
,?GwA@~$k:  
j 3<Ci {3  
public String getSSiteURL() ]es|%j 2  
{ dSGdK $XA  
return sSiteURL; ]\39#  
} #/G!nN #  
~fXNj-'RW  
`^)`J  
public void setSSiteURL(String value) lx`?n<-X  
{ @@ Q4{o  
sSiteURL = value; 8SjCU+V  
} Id=20og  
iJTG +gx  
4E''pW]8  
public String getSFilePath() eb_.@.a  
{ .}dLqw  
return sFilePath; 7U [C=NL  
} JU8}TX  
Za@\=}Tt  
f.g!~wGD  
public void setSFilePath(String value) Pp?P9s {  
{ Q7+WV`&  
sFilePath = value; LK h=jB^bT  
} ) 57'<  
RZz?_1'  
Il =6t  
public String getSFileName() 2"6L\8hd2  
{ oiyvKMHz7  
return sFileName; QytO0K5  
} ?1\5X<|,  
k5RzW4zq;  
WA n@8!9  
public void setSFileName(String value) |r@;ulO  
{ O@$>'Z  
sFileName = value; 2-F7tcya|  
} xU\!UVQ/  
/E6)>y66  
UC&$8^  
public int getNSplitter() ?wtKi#k'v#  
{ xM_#FxJb  
return nSplitter; 2tz4Ag  
} +:Zwo+\kSN  
/M5.Z~|/  
&OU.BR >  
public void setNSplitter(int nCount) rVabkwYD  
{ sX?arI=_U  
nSplitter = nCount; ~D5 -G?%$"  
} '&CZ%&(Gw  
} X "Eqhl<t  
}%KQrlbHJl  
wo9R :kQ  
/* &wNr2PHd#  
**Utility.java n l5+#e*\  
*/ QmBHD;Gf  
package NetFox; X[J<OTj`$  
2K~v`c*4  
>uCO=T,|  
public class Utility { 5]{rim  
@Hj]yb5  
0,0WdJAe  
public Utility()  5+GTK)D  
{ A7QT4h&6  
IlEU6Rs  
mcwd2)  
} s\'t=}0q  
drCL7.j#L  
//线程睡眠 8\il~IFyi  
public static void sleep(int nSecond) hj=n;,a9  
{ 6@Q; LV+  
try{ Tu:lIy~A  
Thread.sleep(nSecond); ^cd bM  
} QP%AJ[3ea%  
catch(Exception e) E:}s 6l  
{ ZrYRLg  
e.printStackTrace (); d3oRan}z  
} xqT} 9,  
} e23&d  
=j_4!^  
//日志 = CXX.%N  
public static void log(String sMsg) __z/X"H  
{ ({4?RtYm  
System.err.println(sMsg); UXa%$gwFw  
} Na\&}GSf^  
"97sH_ ,  
f`}u9!jVR  
public static void log(int sMsg) 0Dd8c \J  
{ s$^ 2Cuhv  
System.err.println(sMsg); GWx?RIKF  
} x!4<ff.  
} 2Z(?pJyDM  
$SLyI$<gP  
Nj;(QhYZ  
/* m=`V  
**TestMethod.java PtjAu  
*/ ubl Y%{"  
package NetFox; j%!xb><  
IFSIQ q  
7vqE @;:dt  
public class TestMethod { yr zyus  
'mU\X!- 4<  
=+e;BYD#!  
public TestMethod() 9dg+@FS}=  
{ ///xx/weblogic60b2_win.exe `=TJw,q  
try{ S{cK~sZj  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'pAq;2AA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ud(w0eX  
SiteFileFetch fileFetch = new SiteFileFetch(bean); enMHKN g  
fileFetch.start(); wh]v{Fi'  
} <.|]%7  
catch(Exception e){e.printStackTrace ();} -P]onD  
O|;|7fCB\  
6%VRQ#g!  
} ]xJ2;{JWsO  
7r3EMX\#Qm  
<l)I% 1T_c  
public static void main(String[] args) "jq F  
{ &>@EfW](  
new TestMethod(); m]++ !  
} M4XU*piz  
} Xt*h2&  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五