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
  • 7031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
/* iV8O<en&i  
**SiteFileFetch.java \z)` pno  
*/ +*P;Vb6D  
package NetFox; J-+p]xG  
import java.io.*; </7_T<He.  
import java.net.*; ZsepTtY  
I85bzzZB  
{\zB'SNq  
public class SiteFileFetch extends Thread { Jb"0P`senY  
e x`mu E  
5Bog\mS  
SiteInfoBean siteInfoBean = null; //文件信息Bean QR]61v:`  
long[] nStartPos; //开始位置 @F%_{6h  
long[] nEndPos; //结束位置 !BikqTM  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 b<?A  
long nFileLength; //文件长度 }_"<2|~_  
boolean bFirst = true; //是否第一次取文件 l Vc':,z  
boolean bStop = false; //停止标志 0R[onPU_vZ  
File tmpFile; //文件下载的临时信息 )k'4]=d <  
DataOutputStream output; //输出到文件的输出流 @F,8M  
gg%9EJpP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 'Xw> ?[BB  
public SiteFileFetch(SiteInfoBean bean) throws IOException sQ8_j  
{ UO{3v ry48  
siteInfoBean = bean; 64h$sC0z/e  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }iCcXZ&5^  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); A*_ |/o  
if(tmpFile.exists ()) )+xHv  
{ lH8e?zJ  
bFirst = false; 8{ iFxTz  
read_nPos(); { WW!P,w  
} 3D/<R|p  
else FR9*WI   
{ U6Ws#e  
nStartPos = new long[bean.getNSplitter()]; #_}r)q  
nEndPos = new long[bean.getNSplitter()]; L:3  
} E3<~C(APW  
FeAMt  
!>Ru= $9  
$2+(|VG4F  
} skR I \  
#:6gFfk0<  
Kx@;LRY#  
public void run() 1l*O;J9By  
{ jVhfpS[  
//获得文件长度 =ijVT_|u0  
//分割文件 )RE~=*?d  
//实例FileSplitterFetch 7y2-8e L  
//启动FileSplitterFetch线程 3om4q2R  
//等待子线程返回 w` ;>+_ E7  
try{ Jg\1(ix  
if(bFirst) .qjdi`v  
{ V)g{ Ew]:  
nFileLength = getFileSize(); 9?~K"+-SI  
if(nFileLength == -1) s$ v<p(yl  
{ "P_PqM  
System.err.println("File Length is not known!"); G)'(%rl  
} ;$= GrR  
else if(nFileLength == -2) |w7D&p$  
{ ~'aK[3  
System.err.println("File is not access!"); :P1/kYg  
} !tL&Ktoj  
else ehCZhi~  
{ uk)6%  
for(int i=0;i<nStartPos.length;i++) =u^{Jvl[  
{ Sd0y=!Pj=  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); v%6mH6V  
} :n t\uwh  
for(int i=0;i<nEndPos.length-1;i++) g9$P J:  
{ hy?e?^  
nEndPos = nStartPos[i+1]; kbF+aS  
} NDv_@V(D  
nEndPos[nEndPos.length-1] = nFileLength; lq%6~va  
} gvx {;e  
} GE0,d  
etHkyF  
A_vf3 *q  
//启动子线程 NtnKS@Ht  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IhYTK%^96  
for(int i=0;i<nStartPos.length;i++) oA1d8*i^E  
{ 6%&RDrn  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U;Ne"Jh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q:4euhz*  
nStartPos,nEndPos,i); qr~= S  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $sX X6K),  
fileSplitterFetch.start(); 82bOiN15  
} `mfN3Q*[c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %G%D[ i]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $_P*Bk)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pd1V8PZSG  
nEndPos = " + nFileLength); #g6*s+Gm  
// fileSplitterFetch[nPos.length-1].start(); VP<_~OLc  
}N6r/ VtOQ  
d^Jf(NE0Yo  
//等待子线程结束 4}\Dr %US  
//int count = 0; ,n &e,I  
//是否结束while循环 `?PpzDV7Y  
boolean breakWhile = false; %bs~%6)  
gqi|k6V/  
MSMgaw?  
while(!bStop) [sT}hYh+  
{ - #ta/*TT:  
write_nPos(); 8eVQnp*  
Utility.sleep(500); HAi'0%"  
breakWhile = true; C"We>!  
Ehv*E  
'n)]"G|  
for(int i=0;i<nStartPos.length;i++) %O<  qw  
{ [H!8m7i;  
if(!fileSplitterFetch.bDownOver) zU7/P|Dw+  
{ b2Jgg&?G  
breakWhile = false; z^q ~|7  
break; ]5=C3Y  
} #el i_Cxe  
} -brn&1oJ  
if(breakWhile) F9SkEf]99  
break; mJ3|UClPS  
xqua>!mqS  
{{\ d5CkX  
//count++; pM^r8kIH  
//if(count>4) zeZ}P>C  
// siteStop(); r^$4]@Wn  
} dIUg e`O9  
k7\h- yn{  
:&/b}b!)AX  
System.err.println("文件下载结束!"); * @QC:1k  
} /4R|QD  
catch(Exception e){e.printStackTrace ();} ?5>Ep:{+/  
} 'z=QV{ni  
q i27:oJ  
-Xw i}/OX  
//获得文件长度 QE.a2 }  
public long getFileSize() B-<H8[GkG1  
{ PJCRvs|X  
int nFileLength = -1; V_SZp8  
try{ i8tH0w/(M  
URL url = new URL(siteInfoBean.getSSiteURL()); K`25G_Y3@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `V;vvHP A  
httpConnection.setRequestProperty("User-Agent","NetFox"); tw`{\kWG  
A;4O,p@   
^@&RJa-kb  
int responseCode=httpConnection.getResponseCode(); km]RrjRp  
if(responseCode>=400) %:P&! F\?  
{ Xiyh3/%yy  
processErrorCode(responseCode); TzCNY@y  
return -2; //-2 represent access is error #Zm%U_$<  
} $Y mD;  
.!\NM&E  
`;@#yyj:_  
String sHeader; )T=cd   
Qo!/n`19  
DKjkO5R\  
for(int i=1;;i++) pm*6&,  
{ bOi`JJ^   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &s|&cT  
//Utility.log(in.readLine()); g]=w_  
sHeader=httpConnection.getHeaderFieldKey(i); 9Okb)K95  
if(sHeader!=null) u_C/Y[ik  
{ SLa\F  
if(sHeader.equals("Content-Length")) ,~!rn}MI<  
{ oM=Ltxv}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xJvM l`2;  
break; QT5,_+ho  
} ?0Qm  
} nJ.<yrzi  
else %CxrXU  
break; S}=euY'i  
} .H,wdzg)  
} `XwFH#_  
catch(IOException e){e.printStackTrace ();} %lw!4Z\gg  
catch(Exception e){e.printStackTrace ();} S z3@h"  
FQbF)K~e  
+$eEZ;4  
Utility.log(nFileLength); Yxal%  
xp395ub6  
-`mHb  
return nFileLength; 8?lp:kM  
} UqaLTdYG  
%n3lm(-0U  
Lh%>> Ht{  
//保存下载信息(文件指针位置) }*2q7K2bj  
private void write_nPos() piRP2Lbm*  
{ p&nIUx"  
try{ CvwC| AW  
output = new DataOutputStream(new FileOutputStream(tmpFile)); uZe|%xK$y  
output.writeInt(nStartPos.length); yW&|ZJF?  
for(int i=0;i<nStartPos.length;i++) A;t6duBDf/  
{ Y5}<7s\UDO  
// output.writeLong(nPos); ( aGwe@AS  
output.writeLong(fileSplitterFetch.nStartPos); %|l^oC+E  
output.writeLong(fileSplitterFetch.nEndPos); Zd/ACZ[  
} ;NrN#<j( !  
output.close(); 8+Y+\XZG  
} .[v4'ww^  
catch(IOException e){e.printStackTrace ();} ,8KD-"l^g  
catch(Exception e){e.printStackTrace ();} 0L "+,  
} PKoB~wLH  
<z3:*=!  
3[RbVT  
//读取保存的下载信息(文件指针位置) 1D42+cy  
private void read_nPos() }";\8  
{ y/>]6Pj  
try{ SArSi6vF  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [@U2a$k+d  
int nCount = input.readInt(); vHY."$|H  
nStartPos = new long[nCount]; 6.z8!4fpl  
nEndPos = new long[nCount]; e}u# :ysj  
for(int i=0;i<nStartPos.length;i++) OPp>z0p%6X  
{ zV(F9}^  
nStartPos = input.readLong(); /dU-$}>ZI  
nEndPos = input.readLong(); 69U[kW&  
} q M( n]{H  
input.close(); D8otU DB{  
} C:77~f-+rQ  
catch(IOException e){e.printStackTrace ();} 9/rX%  
catch(Exception e){e.printStackTrace ();} $z-zscco  
} #]ZOi`;  
0hTv0#j#  
O`nrXC{  
private void processErrorCode(int nErrorCode) <lHelX=/  
{ 6{rH|Z  
System.err.println("Error Code : " + nErrorCode); nRpZ;X)'.  
} ?@"B:#l  
#GBe=tm\K  
sK~d{)+T  
//停止文件下载 &J~vXk: !  
public void siteStop() YYrXLt:  
{ t_@xzt10y  
bStop = true; 'H0b1t1S%  
for(int i=0;i<nStartPos.length;i++) 1LTl=tS#  
fileSplitterFetch.splitterStop(); ;~Eb Q  
J1I"H<}-6  
8iTX}$t\{  
} mOj6 4}_`"  
} *@J  
//负责部分文件的抓取 <(Ub(  
**FileSplitterFetch.java =]h5RC  
*/ }(AgXvRq  
package NetFox; #un#~s 7Q  
M6E.!Cs  
@Oe!*|?mS  
import java.io.*; #4. S2m4  
import java.net.*; $O*rxQ}  
2| u'J  
(\ `knsE!  
public class FileSplitterFetch extends Thread { dQ97O{O:i  
!br0s(|  
?MevPy`H  
String sURL; //File URL &DdFK.lt  
long nStartPos; //File Snippet Start Position |I7-7d-; /  
long nEndPos; //File Snippet End Position .aWEXJ  
int nThreadID; //Thread's ID :]%z8,6k  
boolean bDownOver = false; //Downing is over IxwOzpr  
boolean bStop = false; //Stop identical jq{rNxdGx  
FileAccessI fileAccessI = null; //File Access interface ,^ MA,"8  
gd>Op  
|r"1 &ow5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Sr)rKc  
{ Ic 4>kKh  
this.sURL = sURL; Zfyr& ]"  
this.nStartPos = nStart; {s}@$rW  
this.nEndPos = nEnd; wy5vn?T@  
nThreadID = id; t.m65  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OHeVm-VC  
} * iW>i^  
zR2'xE*  
cDMA#gp  
public void run() "(/ 1]EH`  
{ (,eH*/~/  
while(nStartPos < nEndPos && !bStop) mjbr}9  
{ 2F(zHa  
7Wg0-{yK4  
(q+U5Ls6  
try{ 0eY$K7 U  
URL url = new URL(sURL); *V(TNLIh;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lJ!+n<K+  
httpConnection.setRequestProperty("User-Agent","NetFox"); {uEu ^6a5  
String sProperty = "bytes="+nStartPos+"-"; J2 _DP  
httpConnection.setRequestProperty("RANGE",sProperty); T_CYSS|fX  
Utility.log(sProperty); s$e0;C!D  
@)mH"u!(7  
!n4p*<Y6  
InputStream input = httpConnection.getInputStream(); kQXtO)  
//logResponseHead(httpConnection); gio'_X  
^YzFEu$  
Wd'wL"6De  
byte[] b = new byte[1024]; o >bf7+D  
int nRead; Eh;SH^&6  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !h&A^sAc  
{ (v*$ExF  
nStartPos += fileAccessI.write(b,0,nRead); 9,y*kC  
//if(nThreadID == 1) #"%=7(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _A%} >:q  
} R*I{?+  
VJ P]Jy_  
jJ-j   
Utility.log("Thread " + nThreadID + " is over!"); z8+3/jLN0B  
bDownOver = true;  Z+ [Nco  
//nPos = fileAccessI.write (b,0,nRead); (NUwkAO M}  
} 'M2Jw8i  
catch(Exception e){e.printStackTrace ();} UX=JWb_uGm  
} 'S<ebwRd=  
} 4`uI)N(}*  
+hg|!SS@5  
zRsG$)B  
//打印回应的头信息 A<.`HCv2  
public void logResponseHead(HttpURLConnection con) 0hK)/!Y  
{ Gc}d#oo*k  
for(int i=1;;i++) uNV (r"  
{ pulE6T7 x  
String header=con.getHeaderFieldKey(i); CZg$I&x  
if(header!=null) h0`@yo  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uZ*;%y nQ  
Utility.log(header+" : "+con.getHeaderField(header)); niY9`8  
else nb0V~W  
break; qCOe,$\1/  
} G@b|{!  
} bWAhK@epI  
knZee!FA7  
g&;:[&% T]  
public void splitterStop() "Q]`~u':  
{ T:S+P t~  
bStop = true; 3=V79&  
} RajzH2j+>  
+K2jYgy  
=p|,~q&i  
} ?cf9q@eAH  
75}BI&t3k  
Yd:8i JA  
/* fLl~a[(5  
**FileAccess.java G (Fi  
*//文件访问(定位,写) %c)^8k;I  
package NetFox; k_.%(ZE  
import java.io.*; " cx\P,<  
QcG4~DEX4  
Js[dT|>.  
public class FileAccessI implements Serializable{ d(zBd=;  
W #E-vi+l  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TG'_1m*$  
RandomAccessFile oSavedFile; ^B~z .F i  
long nPos; g|8G!7O  
jV`xRjh  
dM8`!~#&PI  
public FileAccessI() throws IOException w$4fS  
{ }7E2,A9_"  
this("",0); GL'zs8AKf  
} Qc-jOl  
_] veTAV  
 U=MFNp+  
public FileAccessI(String sName,long nPos) throws IOException Oe=7z'o  
{ rI)op1K  
oSavedFile = new RandomAccessFile(sName,"rw");  Hrm^@3  
this.nPos = nPos; z/(^E8F  
oSavedFile.seek(nPos); vL(7|K  
} Gb.r!W8  
Va>~7  
_oxhS!.*  
public synchronized int write(byte[] b,int nStart,int nLen) uFNVV;~RFI  
{ gtWJR  
int n = -1; X*6bsYbK-  
try{ GV'Y'  
oSavedFile.write(b,nStart,nLen); <eK F  
n = nLen; F Cg{!h  
} 9mfqr$3  
catch(IOException e) E'zLgU)r`  
{ rkh+$*t@i7  
e.printStackTrace (); :hB/|H*=  
} ~#+ Hhc(  
JSCe86a7<E  
^=@L(;Y  
return n; M \rW  
} Kf#9-.}?  
:it52*3=  
] P;Ng=a  
} Uc]S7F#  
X-O/&WRYQ  
CEjMHP$=  
/* &OD)e@Tc  
**SiteInfoBean.java E!w%oTx{OR  
*/ `''\FPhh  
package NetFox; V(n7hpS  
qB PUB(  
=Is.T  
public class SiteInfoBean { v:kTZB  
"b5:6\  
yUcWX bT@  
private String sSiteURL; //Site's URL 8%v1[W i  
private String sFilePath; //Saved File's Path _Vr>/f  
private String sFileName; //Saved File's Name &|'k)6Rx  
private int nSplitter; //Count of Splited Downloading File |%.V{vgP7  
.jW+\mIX  
 K9 h{sC  
public SiteInfoBean() IF-g %  
{//nSplitter的缺省值为5 FY h+G-Y#  
//default value of nSplitter is 5 udYk 6  
this("","","",5); +Zgh[a  
} 9M{z@H/  
nw|ls2   
[O92JT:li  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) | wuUH  
{ eCHT) 35u  
sSiteURL= sURL; W,'30:#Fr7  
sFilePath = sPath; H|&[,&M>  
sFileName = sName; w3oh8NRs_  
this.nSplitter = nSpiltter; z 4 4(  
k4Ed7T-  
<RQ\nU  
} `{BY {  
= rDoXm  
HAJK%zLc  
public String getSSiteURL() CYD&#+o  
{ 8wJfG Y  
return sSiteURL; ;G!JKg  
} ]Q-*xho  
CtiTXDc_  
$<&N#  
public void setSSiteURL(String value) <2Q+? L{  
{ 1#BMc%  
sSiteURL = value; >;I$&  
} zyb>PEd.  
GSck^o2{  
^i>Tm9vM  
public String getSFilePath() (Q~ p"Ch  
{ 8{QN$Qkn  
return sFilePath; |/rms`YQ  
} )xKZ)SxV  
}U-h^x'  
Z_^i2eJYT  
public void setSFilePath(String value) K]5@bm  
{ ;la sk4|  
sFilePath = value; Xtv^q> !  
} M:&g5y&  
RlJt+lnV  
UbDRzum  
public String getSFileName() $2lrP]`>j.  
{ <7-Qn(m,  
return sFileName; zF'LbQz0[  
} Lh eOGM  
DL$O274uZ  
XNODDH   
public void setSFileName(String value) `<}Q4p  
{ dV_ClH &)  
sFileName = value; ECq(i(  
} _J' _9M?>  
Vu6$84>-,  
NrQGoAOw  
public int getNSplitter() -2Bkun4Pt  
{ #6w\r&R6  
return nSplitter; %NH#8#';2  
} O"%b@$p\L  
3QNu7oo  
|"t)#BUtL  
public void setNSplitter(int nCount) 1>5l(zK!9  
{  hsYS<]  
nSplitter = nCount; U tb"6_   
} L;jzDng<  
} :x85:pa  
,mkXUW  
|%p;4b  
/* l;+nL[%`  
**Utility.java M1UabqQ  
*/ b8Bf,&:ys  
package NetFox; 9@'^}c#  
(6b*JQ^^  
uO=yQ&  
public class Utility { hn-+]Y:  
{, +,:w7  
6M sVV_/  
public Utility() 5W%^g_I  
{ Y z"B  
\PHbJN:BI  
+MHsdeGU1W  
} : T` Ni  
/#WRd}IjK  
//线程睡眠 a| w.G "W  
public static void sleep(int nSecond) W8bh49   
{ (T&rvE  
try{ j` RuK  
Thread.sleep(nSecond); F6g)2&e{/  
} 8\V  
catch(Exception e) S}mZU!  
{ h!@t8R  
e.printStackTrace (); 3 VNPdXsh  
} ]'  ck!eG  
} S_ELZO#7  
c)L1@qdZ  
//日志 NOzAk%s3I  
public static void log(String sMsg) ,tZJSfHB  
{ kfb*|  
System.err.println(sMsg); c%?31 t  
} 2=?:(e9  
$9~6M*  
H YA<  
public static void log(int sMsg) _BC%98:WP  
{ Ln&'5D#  
System.err.println(sMsg); 0ZRIi70u  
} *!mT#Vm^  
} QB3vp4pBg@  
7IEG%FY T  
A(j9T,!  
/* oR``Jiob|  
**TestMethod.java _lK+/"-l  
*/ H{tG:KH  
package NetFox; Bsr; MVD  
Npr<{}ZE  
[m*E[0Hu  
public class TestMethod { PM(M c]6  
AbqeZn  
^/"[jq3F  
public TestMethod() QGC%, F"+  
{ ///xx/weblogic60b2_win.exe Ne!0`^`~  
try{ 6}q8%[l|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6jDHA3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PN(P$6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )(4.7>  
fileFetch.start(); E((U=P}+g  
} goJK~d8M*  
catch(Exception e){e.printStackTrace ();} Xc>M_%+ R  
VuU{7:  
47/14rY 2  
} +VE ] .*T  
{ /u}  
k Q Sx65  
public static void main(String[] args) mi`jY0e2  
{ `]T# uP<u  
new TestMethod(); zyHHz\{  
} vq?aFX9F  
} P5$L(x%~  
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:
3+5=?,请输入中文答案:八 正确答案:八