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
  • 9385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
/* H|B4.z  
**SiteFileFetch.java &qeM YYY  
*/ GEfTs[  
package NetFox; 4p/d>DTiM  
import java.io.*; 4ko(bW#jL  
import java.net.*; =a./HCF  
-(![xZ1{K  
kM@heFJb.  
public class SiteFileFetch extends Thread { 2NqO,B|R  
p GSS   
iED gcg7  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~@ hiLW  
long[] nStartPos; //开始位置 }tH6E  
long[] nEndPos; //结束位置 GMoE,L  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g h&,U`  
long nFileLength; //文件长度 :+}Eo9  
boolean bFirst = true; //是否第一次取文件 Jg%jmI;Y  
boolean bStop = false; //停止标志 d} ]jw4  
File tmpFile; //文件下载的临时信息 Qw/H7fvh&  
DataOutputStream output; //输出到文件的输出流 Ceak8#|4  
|jyoT%SQ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =(>pv,  
public SiteFileFetch(SiteInfoBean bean) throws IOException p3{ 3[fDx  
{ Q.L.B7'e7  
siteInfoBean = bean; I>3]VR i  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Z"'tJ3Y.~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); LO M-i>  
if(tmpFile.exists ()) xy1R_*.F^T  
{ y[sO0u\  
bFirst = false; 8Ir = @  
read_nPos(); ,hXhcfFl  
} ir3EA'_>N  
else <Yy|.=6 D  
{ yj C@  
nStartPos = new long[bean.getNSplitter()]; :/'oh]T|  
nEndPos = new long[bean.getNSplitter()]; +HNM$yp  
} $/;;}|hqi  
InR/g@n+D1  
"E )0)A3=  
JQ]A"xTIa*  
} WkR=(dss8  
)Fh5*UC  
\L{V|}"X  
public void run() yMbg1+:   
{ ;*XH[>I  
//获得文件长度 VRa>bS  
//分割文件 |jE0H!j  
//实例FileSplitterFetch +yo1&b R/  
//启动FileSplitterFetch线程 T:(c/ >  
//等待子线程返回 'Q F@@48  
try{ #Vi:-zyY  
if(bFirst) Y|96K2BR  
{ Z`Sbq{Kx  
nFileLength = getFileSize(); L4-v'Z;  
if(nFileLength == -1) :LEC[</yvl  
{ As-xO~+  
System.err.println("File Length is not known!"); C;NG#4;'  
} -7:_Dy  
else if(nFileLength == -2) (S1Co&SX  
{ C(kIj  
System.err.println("File is not access!"); ct![eWsuB  
} ~zT743  
else R\d)kcy4  
{ sW]fPa(cn,  
for(int i=0;i<nStartPos.length;i++) aJ^RY5  
{ ]KE"|}B  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); B(h%>mT[  
} TdWatvY5p  
for(int i=0;i<nEndPos.length-1;i++) ,@4~:OY  
{ \RDS~u\d  
nEndPos = nStartPos[i+1]; C4^o= 6{  
} 6#DDMP8;I  
nEndPos[nEndPos.length-1] = nFileLength; X{G&r$  
} {<1 ]cP  
} y$C\b\hM  
ErXzKf  
u</LgOP`-  
//启动子线程 -oR P ZtW  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R /0zB  
for(int i=0;i<nStartPos.length;i++) ZF~@a+o  
{ ,37\8y?o\  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5VR=D\j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qz6@'1  
nStartPos,nEndPos,i); K#!c<Li#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .bvEE  
fileSplitterFetch.start(); dcbE<W#ss  
} &Y3 r'"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ap|$8 G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aT"0tn^LO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^(on"3sG  
nEndPos = " + nFileLength); !b4v}70,  
// fileSplitterFetch[nPos.length-1].start(); ~duF2m 72  
!rZ r:@  
5l[&-: (Lh  
//等待子线程结束 ,Vr-E  
//int count = 0; zqt{oN_  
//是否结束while循环 xfK@tLEZ-1  
boolean breakWhile = false; ptMDhMVW  
e-Ma8+X\  
iininITOS{  
while(!bStop) ykat0iqo  
{ ;Qq<5I"y  
write_nPos(); m;@8z[ ^5  
Utility.sleep(500); f1,VbuS9I  
breakWhile = true; BOdd~f%&tn  
^2)<H7p  
 xh|<`>5  
for(int i=0;i<nStartPos.length;i++) &UfP8GE9  
{ RBOg;EJ  
if(!fileSplitterFetch.bDownOver) iV2v<ap.n  
{ !\Vc#dslt  
breakWhile = false; &\ $~  
break; )wyC8`&-  
} -"uOh,G}  
} 7*\Cf qrU  
if(breakWhile) n5>OZ3 E@  
break; HP2J`>oo  
!hWS%m@  
IF'Tj`yD  
//count++; o'J^kd`  
//if(count>4) *!m(oP  
// siteStop(); u1;sH{YK>  
} JpE7"Z"~MS  
hAU@}"=G  
34<k)0sO  
System.err.println("文件下载结束!"); y/>IF|aX  
} \zLKSJ]  
catch(Exception e){e.printStackTrace ();} [PX%p ;"D  
} nAaY5s0D  
xVN(It7g  
buKSZ  
//获得文件长度 ]e6$ ={  
public long getFileSize() Q4ZKgcC  
{ @id!F<+%oD  
int nFileLength = -1; H;{IOBo  
try{ IN7Cpg~9%  
URL url = new URL(siteInfoBean.getSSiteURL()); B]u!BBjC  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,{2= nb[  
httpConnection.setRequestProperty("User-Agent","NetFox"); -an~&C5\  
 !U=o<)I  
l/-qVAd!q  
int responseCode=httpConnection.getResponseCode(); wQX18aF/#d  
if(responseCode>=400) t$z 5m<8  
{ pS+hE4D  
processErrorCode(responseCode); Te2 C<c  
return -2; //-2 represent access is error (tvfF0~  
} (lg~}Jwq  
N$N 7aE$  
%E2V$l0  
String sHeader; d.$0X/0  
Q8D#kAYw  
_E2W%N  
for(int i=1;;i++) {PKf]m  
{ r T_J6F5J  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rT(b t~Z  
//Utility.log(in.readLine()); EGVS8YP>h  
sHeader=httpConnection.getHeaderFieldKey(i); LK+67Y{25  
if(sHeader!=null) @{{6Nd5  
{ >S>B tR l  
if(sHeader.equals("Content-Length")) bF'Jm*f  
{ DT3"uJTt  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~,7Tj  
break; %>!W+rO,  
} KAg-M#  
} 9AJ"C7  
else K57u87=*X?  
break; MU:q`DRr  
} =[,EFkU?B  
} MdhD "Q  
catch(IOException e){e.printStackTrace ();} Q zp!)i  
catch(Exception e){e.printStackTrace ();} RQ;w$I\  
$Y M(NC  
9Ed=`c  
Utility.log(nFileLength); k)R~o b  
SP"t2LTP  
*Hz]<b?  
return nFileLength; fd$nAE  
} upnX7as  
,\T7{=ZG\!  
A1n4R  
//保存下载信息(文件指针位置) _+,>NJ  
private void write_nPos() i0F6eqe=J  
{ n0Qp:_2z  
try{ &v#pS!UOj  
output = new DataOutputStream(new FileOutputStream(tmpFile)); f2u4*X E\  
output.writeInt(nStartPos.length); g@Pq<   
for(int i=0;i<nStartPos.length;i++) Y`."=8R~  
{ P9W?sPnC5  
// output.writeLong(nPos); t;`ULp~&  
output.writeLong(fileSplitterFetch.nStartPos); /ke[nr  
output.writeLong(fileSplitterFetch.nEndPos); Z7>Nd$E{  
} E24j(>   
output.close(); i.{.koH<  
} Rn)fwGC  
catch(IOException e){e.printStackTrace ();} OIDP#K  
catch(Exception e){e.printStackTrace ();} rl,i,1t  
} _nM 7SK  
Hk'R!X  
3YG%YhevO  
//读取保存的下载信息(文件指针位置) (8~D ^N6Z  
private void read_nPos() a"l\_D'.K8  
{ UF$O@l  
try{ "7eL&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g7{:F\S  
int nCount = input.readInt(); dQ_hlx!J  
nStartPos = new long[nCount]; (|>rDk;  
nEndPos = new long[nCount]; izzX$O[=:  
for(int i=0;i<nStartPos.length;i++) Tgl >  
{ R90#T6^  
nStartPos = input.readLong(); V|~o`(]  
nEndPos = input.readLong(); @}2EEo#  
} 51tZ:-1!  
input.close(); |{JI=$  
} Shv$"x:W  
catch(IOException e){e.printStackTrace ();} OZA^L;#>  
catch(Exception e){e.printStackTrace ();} WrS>^\:  
} 6AoKuT;  
IJVzF1vC  
[] el4.J,  
private void processErrorCode(int nErrorCode) lF t^dl^  
{ "dT"6,  
System.err.println("Error Code : " + nErrorCode); 10)RLh|+  
} {T-^xwc  
'rTJ*1i  
GaV}@Q  
//停止文件下载 hxMV?\MYj  
public void siteStop() &;~?\>?I  
{ i[ >U#5  
bStop = true; ^C92R"*Qu  
for(int i=0;i<nStartPos.length;i++) 3 NFo=Z8  
fileSplitterFetch.splitterStop(); y` {|D*  
bDm7$ (  
*Q)-"]O(k  
} " %qr*|  
} :K5?&kT  
//负责部分文件的抓取 D)Ep!`Q   
**FileSplitterFetch.java )U7fPKQ  
*/ 1wm`a  
package NetFox; /='Q-`?9  
hC9EL= A  
?z2!?  
import java.io.*; BMqr YW  
import java.net.*; 7t1as.  
/]U;7)  
(G/(w%#7_  
public class FileSplitterFetch extends Thread { &H P g>  
|sY  
gVe]?Jva`  
String sURL; //File URL E-($Xc  
long nStartPos; //File Snippet Start Position <EQaYZY=  
long nEndPos; //File Snippet End Position z;y{QO  
int nThreadID; //Thread's ID s;..a&C'  
boolean bDownOver = false; //Downing is over R7K`9 c1f6  
boolean bStop = false; //Stop identical Fq_>}k@fI  
FileAccessI fileAccessI = null; //File Access interface ,L lYRj 5  
uE<8L(*B  
^B%c3U$o  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 00{a }@n  
{ B:Ft(,  
this.sURL = sURL; W#E(?M[r  
this.nStartPos = nStart; h"/'H)G7_&  
this.nEndPos = nEnd; 2W`WOBz  
nThreadID = id; Xs# _AX  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JWYe~  
} cy)-Rfg  
![nL/  
S;jD@j\t&  
public void run() QqRF?%7q"q  
{ cTS.yN({G  
while(nStartPos < nEndPos && !bStop) \#WWJh"W  
{ : p)R,('g  
ij! ],  
D4C:%D  
try{ 7qZC+x6_L  
URL url = new URL(sURL); -FI)o`AE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }2;iIw`  
httpConnection.setRequestProperty("User-Agent","NetFox"); <:NahxIlu  
String sProperty = "bytes="+nStartPos+"-"; :WX OD  
httpConnection.setRequestProperty("RANGE",sProperty); u|T]Ne  
Utility.log(sProperty); /zb/ am1#  
(z.n9lkfi  
^)I}#  
InputStream input = httpConnection.getInputStream(); G;iH.rCH  
//logResponseHead(httpConnection); KO%$  
W$2 \GPJt  
?Z_T3/ f  
byte[] b = new byte[1024]; Kh[l};/F  
int nRead; F\^8k/0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SDV#p];u  
{ LMx/0  
nStartPos += fileAccessI.write(b,0,nRead); l2:-).7xt  
//if(nThreadID == 1) 3;VH'hh_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,msP(*qoI  
} 1G"ohosmF  
*S"RU~1_  
Jwfb%Xge~  
Utility.log("Thread " + nThreadID + " is over!"); %8h=_(X\7  
bDownOver = true;  <7SE|  
//nPos = fileAccessI.write (b,0,nRead); /e[m;+9^&  
} zi3v, Kq  
catch(Exception e){e.printStackTrace ();} iETUBZ  
} X7AxI\h  
} WcoA)we  
M_Q`9  
ZSW@,Ti  
//打印回应的头信息 P+ CdqOL  
public void logResponseHead(HttpURLConnection con) Maq`Or|4  
{ L+p}%!g  
for(int i=1;;i++) Q{?\qCrrYl  
{ dNNXMQ0"  
String header=con.getHeaderFieldKey(i); [@5cYeW3.  
if(header!=null) `2LmLFkb  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2G$p x  
Utility.log(header+" : "+con.getHeaderField(header)); fP5i3[T  
else 5>+@.hPX  
break; TfT^.p*  
} ?jUgDwc(w  
} }$ySZa9  
.r{t&HO;Y  
M2p|&Z%  
public void splitterStop() 8<mloM-4  
{ YY:{/0?  
bStop = true; yn$1nt4  
} iE HWD.u  
xw_klHL-o  
pe0ax- Zv  
} }/&Zo=Q$  
:$k1I-^R  
]' [:QGr  
/* pfHjs3A=  
**FileAccess.java y6tqemz  
*//文件访问(定位,写) yP"}(!~m  
package NetFox; |;xEK nF  
import java.io.*; JbL3/h]  
&9)/"  
i%.k{MY  
public class FileAccessI implements Serializable{ bf+C=A)s0  
ymqv@Byi8A  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %K')_NS@  
RandomAccessFile oSavedFile; n44 T4q  
long nPos; EyVu-4L:#  
m BFNg3_  
kP+,x H)1  
public FileAccessI() throws IOException /;+\6(+X  
{ 3@\/5I xn  
this("",0); e)B1)c8s  
} B>>_t2IU  
`|>]P"9yp  
>'W,8F  
public FileAccessI(String sName,long nPos) throws IOException "{qnm+G  
{ ,$ /Ld76U  
oSavedFile = new RandomAccessFile(sName,"rw"); GiX3c^V"1  
this.nPos = nPos; MGMJeq vr  
oSavedFile.seek(nPos); {*F =&D  
} JxwKTFU'3O  
!J<Xel {  
21tv(x  
public synchronized int write(byte[] b,int nStart,int nLen) J&fIW Z  
{ 4-SU\_  
int n = -1; k<Gmb~Tg1  
try{ i 0/QfB%O  
oSavedFile.write(b,nStart,nLen); b way+lh  
n = nLen; <!FcQVH+L  
} ]s0wJD=  
catch(IOException e) zps =~|  
{ / 7\q#qIm:  
e.printStackTrace (); xok T  
} f4\$<g/~  
9ghzK?Yc  
X"d"a={]  
return n; y3 b"'-%  
} m4oj1h_4  
]tT=jN&(  
y[85eM  
} qQ^CSn98J  
B-w`mcqp$  
u9KT_` )  
/* G^nG^HTo5  
**SiteInfoBean.java ^gx~{9`RR  
*/ xBc|rqge  
package NetFox; -O?HfQ  
C F','gPnc  
N8At N\e  
public class SiteInfoBean { IMbF]6%p(  
5o 5DG  
=cS5f#0  
private String sSiteURL; //Site's URL "GZ}+K*GG  
private String sFilePath; //Saved File's Path  %V ]v,  
private String sFileName; //Saved File's Name h M7 SGEV  
private int nSplitter; //Count of Splited Downloading File 9#P~cW?  
y7:f^4  
K/Yeh<_&  
public SiteInfoBean() ![ce }  
{//nSplitter的缺省值为5 y[.lfW?)  
//default value of nSplitter is 5 EGqu-WBS  
this("","","",5); z-kv{y*Hu  
} C=r`\W  
X41Qkf{  
 <a $!S  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N}%AUm/L  
{ *j]Bo,AC  
sSiteURL= sURL; zn^7#$fC  
sFilePath = sPath; 7L&,Na  
sFileName = sName; 0]*W0#{Zj  
this.nSplitter = nSpiltter; $t^Td<  
y `FZ 0FI  
Q njK<}M9  
} T^#d;A  
1aS:bFi`  
nlhv  
public String getSSiteURL() WO9vOS>  
{ OAs>F"  
return sSiteURL; 3bezYk  
} " ]G'^  
2;>uP#1]  
h%u!UHA  
public void setSSiteURL(String value) +J C"@  
{ `3ha~+Goo!  
sSiteURL = value; 9-{+U,3)  
} d9S?dx  
w=(dJ(7gu  
BNjMq  
public String getSFilePath() H.XyNtJ  
{ "}1cQ|0a  
return sFilePath; km9#lK  
} /KC^x= Xv:  
BNE:,I*&  
kZG; \  
public void setSFilePath(String value) hQe78y  
{ G)[gLD{g?  
sFilePath = value; xLFMC?I  
} $rk=#;6]v;  
!ck~4~J  
D :j5/ *  
public String getSFileName() qzORv  
{ --"5yGOL  
return sFileName; zfI{cMn'J  
} YI*H]V%w  
 G$'UK  
9]ZfSn)  
public void setSFileName(String value) (-0d@eqw  
{ q({-C  
sFileName = value; Tf!6N<dRXR  
} VByA6^JR  
;Dp*.YJ  
CfS;F  
public int getNSplitter() ;PG= 3j_  
{ vv2[t  
return nSplitter; _8y4U  
} .p=J_%K}0x  
0[d*Z  
AU)\ lyB  
public void setNSplitter(int nCount) ! jAp V  
{ QR(;a:  
nSplitter = nCount; hP WP6;Z  
} S2|pn\0V  
} V\L%*6O  
&$2d=q8mh  
zBq&/?  
/* A7#nBHwxZ  
**Utility.java Y=Ic<WHR  
*/ ^fO9oPM|  
package NetFox; KwaxNb5  
5`e;l$ M`  
](n)bF+ym  
public class Utility { !PeSnO  
qhTVsZ:{C  
 _}JMBIq$  
public Utility() T YR \K  
{ wBw(T1VN  
Iy;"ht6  
PU%f`)  
} jHE^d<=O^  
z#`Qfvu6Hi  
//线程睡眠 tUOY`]0  
public static void sleep(int nSecond) Nc[N 11?O  
{ Zw{?^6;cS  
try{ GNuIcy  
Thread.sleep(nSecond); j -"34  
} TUwX4X6m  
catch(Exception e) N8kNi4$mp=  
{ V'dw=W17V  
e.printStackTrace (); :eL[nyQr  
} =~W=}  
} ci2Z_JA+  
[FF}HWf  
//日志 Z 1wtOL  
public static void log(String sMsg) 3Ur_?PM+C  
{ n!SHExBp  
System.err.println(sMsg); *]R5bj.!o  
} `Xeiz'~f8  
=E!Y f#p+q  
5wAKA`p"z  
public static void log(int sMsg) ! N!pvK;  
{ r: >RH,  
System.err.println(sMsg); mqsAYzG  
} ,H.5TQ#  
} h0dZr-c  
[742s]j  
Nr*X1lJ6  
/* w?8\9\ ;?  
**TestMethod.java A1Uy|Dl  
*/ B1U!*yzG6  
package NetFox; GNrRc3dr$  
l. cp[  
cvT@`1  
public class TestMethod { H n]( )/  
?tqJkL#  
uF}B:53A  
public TestMethod() b3 =Z~iLv  
{ ///xx/weblogic60b2_win.exe [MbbL  
try{ +kE~OdZG  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (G{S*+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2cIbX  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1 \aTA,  
fileFetch.start(); dXM8iP  
} PrfG  
catch(Exception e){e.printStackTrace ();} 0n kC%j  
gE^pOn  
3 4%B0  
} IqepR >5t  
PXtF#,roP  
3X DU(#  
public static void main(String[] args) }hg2}g99  
{ O8" t.W  
new TestMethod(); o%;ly  
} ~a_X 7  
} T"X]@9g^-  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八