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
  • 10498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
/* ";o~&8?)  
**SiteFileFetch.java 7WXiG0  
*/ (&k') ff9K  
package NetFox; .a5X*M]  
import java.io.*; 5%'o%`?i  
import java.net.*; am3V9 "\  
w{~" ;[@  
1R*1BStc  
public class SiteFileFetch extends Thread { QP'qG@j[:  
9OH.&g  
`..EQ BM  
SiteInfoBean siteInfoBean = null; //文件信息Bean z_'dRw  
long[] nStartPos; //开始位置 \G]K,TG  
long[] nEndPos; //结束位置 bKTqX[=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Sio1Q0  
long nFileLength; //文件长度 ykJ+%gla  
boolean bFirst = true; //是否第一次取文件  z I(xSX@  
boolean bStop = false; //停止标志 g^qz&;R]  
File tmpFile; //文件下载的临时信息 .iN-4"_j1  
DataOutputStream output; //输出到文件的输出流 vs* >onCf  
*13g <#$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) u4@, *tT  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2m|Eoc&M_  
{ K6ciqwUO  
siteInfoBean = bean; YcPKM@xo  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); \m@] G3=]  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /FoUo   
if(tmpFile.exists ()) t$tsWAmiA[  
{ ' l|41wxk  
bFirst = false; dvC0 <*V  
read_nPos(); ex{)mE4Cd  
} Fka1]|j9  
else k>7gy?Y!K<  
{ u}^a^B$  
nStartPos = new long[bean.getNSplitter()]; llHN2R%(  
nEndPos = new long[bean.getNSplitter()]; 4 fZY8  
} K<D`(voL  
lp?i_p/z  
8.:B=A  
Q S5dP  
} P)a("XnJ`  
 <WO&$&  
?a*fy}A|  
public void run() zw}@nqp   
{ cb\jrbj6  
//获得文件长度 ^- u[q- !  
//分割文件 5`(((_Um+  
//实例FileSplitterFetch +oE7~64LL  
//启动FileSplitterFetch线程 -bv>iIC  
//等待子线程返回 ,w,ENU0~f  
try{ SJso'6 g  
if(bFirst) K-N]h  
{ A9NOeE  
nFileLength = getFileSize(); +8MW$ m$  
if(nFileLength == -1) H(  
{ =1%zI%  
System.err.println("File Length is not known!"); d/"gq}NT  
} R>Z,TQU  
else if(nFileLength == -2) +s#S{b  
{ aS c#&{  
System.err.println("File is not access!"); A@9U;8k  
} &*Q|d*CP  
else rhlW  
{ >1#DPU(g  
for(int i=0;i<nStartPos.length;i++) lCM6T;2ID  
{ 9O(i+fM  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); sURUQ  H  
} c#]'#+aH  
for(int i=0;i<nEndPos.length-1;i++) 2U-#0,ll]  
{ p.6$w:eV  
nEndPos = nStartPos[i+1]; Y\ #.EVz  
} i{Y=!r5r  
nEndPos[nEndPos.length-1] = nFileLength; Z"teZ0H  
} ]>]#zu$=c  
} QO1A976o  
6i*ArGA   
S3%.-)ib  
//启动子线程 .WN;TjEg!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I!C(K^  
for(int i=0;i<nStartPos.length;i++) qat45O4A1  
{ {hW +^  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~9`^72  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g=8|z#S  
nStartPos,nEndPos,i); ):|G k Sm  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TFiuz; *|  
fileSplitterFetch.start(); 7I2a*4}  
} SX1Fyy6 w  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T! &[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rahHJp.Ws  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7Va#{Y;Zy  
nEndPos = " + nFileLength); n?<# {$  
// fileSplitterFetch[nPos.length-1].start(); .N2nJ/   
EOd.Tyb!/  
*IMF4 x5M  
//等待子线程结束 Pj1K  
//int count = 0; =]5DYRhX]  
//是否结束while循环 y]~+`9  
boolean breakWhile = false; S0Rf>Eo4  
G#9o?  
}J'5EAp  
while(!bStop) a<a&6 3  
{ E.7AbHph0  
write_nPos(); e')&ODQ H  
Utility.sleep(500); nN_94 ZqS<  
breakWhile = true; !Vp,YN+yN  
^C,/T2>  
D7gX,e  
for(int i=0;i<nStartPos.length;i++) _D7HQ  
{ H3UX{|[  
if(!fileSplitterFetch.bDownOver) o2 T/IJP  
{ 7Ap~7)z[  
breakWhile = false; Mc#O+'](f  
break; vV:M S O'r  
} WwCK  K  
} LX(iuf+l  
if(breakWhile) 4z-,M7iP  
break; >[E|p6jgT  
Mo/2,DiI5  
 "df13U"  
//count++; A .jp<>  
//if(count>4) \gJapx(  
// siteStop(); Hb@G*L$  
} 7(+OsE  
e GqvnNv  
pjmGzK  
System.err.println("文件下载结束!"); }LHT#{+ x  
} &bS"N)je  
catch(Exception e){e.printStackTrace ();} @gu77^='  
} }jyS\drJ  
(to/9OrG  
0$F _hZU  
//获得文件长度 0^)8*O9$  
public long getFileSize() E{+c*sz  
{ 98b9%Z'2f  
int nFileLength = -1; Z)6nu)  
try{ ZB_16&2Ow  
URL url = new URL(siteInfoBean.getSSiteURL()); \^;|S  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gn[$;*932z  
httpConnection.setRequestProperty("User-Agent","NetFox");  n_xa)  
SG+i\yu$h0  
\/x)BE,  
int responseCode=httpConnection.getResponseCode(); 6ljRV)  
if(responseCode>=400) *k@0:a(>  
{ |/T<]+X;  
processErrorCode(responseCode); JQbMw>Y  
return -2; //-2 represent access is error ]` &[Se d  
} D"( 3VIglq  
ai;gca_P#  
Vx7Dl{?{'  
String sHeader; {Y@-*pL]  
hI>rtaY_  
.1[2 CjQ  
for(int i=1;;i++) hklO:,`  
{ dPyBY ]`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  z7.C\l  
//Utility.log(in.readLine()); faL^=CAe  
sHeader=httpConnection.getHeaderFieldKey(i); gQk#l\w _  
if(sHeader!=null) ~d#;r5>  
{ Y+"hu2aPkY  
if(sHeader.equals("Content-Length")) [ilv/V<  
{ &"H<+>`  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x9o^9QJh  
break; xJH9qc ME  
} @cTZ`bg  
} 'j,Li(@}  
else OCOO02Wq1  
break; 4f*Ua`E_  
} p$b= r+1f  
} !ovZ>,1  
catch(IOException e){e.printStackTrace ();} cJ(zidf_$  
catch(Exception e){e.printStackTrace ();} \dxW44sM  
pD}VB6=  
_G}CD|Kx  
Utility.log(nFileLength); }r<@o3t  
{GH`V}Ob  
x}8T[  
return nFileLength; n.8A Ka6  
} +O!M>  
&"j).Ogm4  
G}?P r4Gj  
//保存下载信息(文件指针位置) >y06s{[  
private void write_nPos() @#ho(_U8  
{ l]kl V+9t  
try{ Bg+]_:<U  
output = new DataOutputStream(new FileOutputStream(tmpFile)); D-+)M8bt  
output.writeInt(nStartPos.length); D'sboOY  
for(int i=0;i<nStartPos.length;i++) Cp~3Jm3  
{ B 1ZHV^  
// output.writeLong(nPos); 4M<JfD  
output.writeLong(fileSplitterFetch.nStartPos); m|cWX"#g  
output.writeLong(fileSplitterFetch.nEndPos); b\|p  
} PHiX:0zT  
output.close(); cT=wJ  
} L};;o+5uJD  
catch(IOException e){e.printStackTrace ();} ,w/mk$v  
catch(Exception e){e.printStackTrace ();} MCrO]N($b  
} l^eNZ3:H  
<1 1Tqb  
O]%m{afM  
//读取保存的下载信息(文件指针位置) a_iQlsU  
private void read_nPos() xP/1@6]_Je  
{ |`t!aG8  
try{ C7 & 6rUX  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^B6i6]Pd=9  
int nCount = input.readInt(); n.qxxzEN  
nStartPos = new long[nCount]; Z"%O&O  
nEndPos = new long[nCount]; ; R|#ae@  
for(int i=0;i<nStartPos.length;i++) ~ :b:_ 5"  
{ >LaL! PnZ  
nStartPos = input.readLong(); 1q233QSW)  
nEndPos = input.readLong(); =&*QT&e  
} ~G ^}2#5  
input.close(); QB|fFj58u  
} .lF\bA|  
catch(IOException e){e.printStackTrace ();} =wR]X*Pan  
catch(Exception e){e.printStackTrace ();} 46?F+,Rzl  
} U#]eN[  
Py25k 0j!  
c'Tu,-  
private void processErrorCode(int nErrorCode) 7D~O/#dcc  
{ SnF[mN'  
System.err.println("Error Code : " + nErrorCode); _Il9s#NA%  
} q fH~hg  
0|>  
|e[0Qo@  
//停止文件下载 xjbyI_D  
public void siteStop() 0S5C7df  
{ _} 9R}  
bStop = true; >=W#z  
for(int i=0;i<nStartPos.length;i++) JO^ [@  
fileSplitterFetch.splitterStop(); ^FMa8;'o  
.rB;zA;4S)  
]3y5b9DuW  
} &MQt2aL  
} #`L}.  
//负责部分文件的抓取 &eS70hq  
**FileSplitterFetch.java 6'*Uo:]  
*/ /uz5V/i0  
package NetFox; ?N?pe}  
= SJF \Z  
%iS]+Sa.K  
import java.io.*; +2fJ  
import java.net.*; @[kM1:G-F{  
Jx>B %vZ\  
pD6g+Taj  
public class FileSplitterFetch extends Thread { ;I))gY-n  
DfzUGX  
xv%USm  
String sURL; //File URL )W6- h  
long nStartPos; //File Snippet Start Position 3XlnI:w =  
long nEndPos; //File Snippet End Position MMr7,?,$  
int nThreadID; //Thread's ID '=5_u  
boolean bDownOver = false; //Downing is over 5 /jY=/0.a  
boolean bStop = false; //Stop identical a<"& RnG(  
FileAccessI fileAccessI = null; //File Access interface ?_j6})2zY  
p}zk&`  
sCCr%r]zL  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vrnj}f[h  
{ nK'8Mo  
this.sURL = sURL; %+B-Z/1}  
this.nStartPos = nStart; vG_v89t!ex  
this.nEndPos = nEnd; 0t[mhmSU,  
nThreadID = id; sr@XumT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }_/h~D9-T#  
} ^W[`##,{Od  
4-rI4A<  
C(*@-N pf[  
public void run() j=QR*8*  
{ 2/4x]i H*  
while(nStartPos < nEndPos && !bStop) .'mC3E+ $  
{ S,9WMti4x  
14YV#o:  
-x\l<\*  
try{ c%/&@vs7  
URL url = new URL(sURL); UVmyOC[Y{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d?y\~<  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0@x$Cp  
String sProperty = "bytes="+nStartPos+"-"; B:#0B[  
httpConnection.setRequestProperty("RANGE",sProperty); ~)IJE+e>}  
Utility.log(sProperty); WJ4UJdf'  
@%G"i:HZ&  
`/ReJj&~  
InputStream input = httpConnection.getInputStream(); uWtS83i  
//logResponseHead(httpConnection); 2pNJWYW"  
)bU")  
fvMhq:Bu  
byte[] b = new byte[1024]; bK;a V&  
int nRead; IeI% X\G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |A/_Qe|s2  
{ |Pl{Oo+  
nStartPos += fileAccessI.write(b,0,nRead); [Q_| 6Di  
//if(nThreadID == 1) /~huTKA}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LF.~rmPa  
} HtYR 0J  
n]c,0N  
'wlP`7&Tn  
Utility.log("Thread " + nThreadID + " is over!"); 6U9Fa=%>}  
bDownOver = true; X&oy.Roo  
//nPos = fileAccessI.write (b,0,nRead); -vfu0XI~  
} mf[79:90^  
catch(Exception e){e.printStackTrace ();} o? "@9O?  
} WvzvGT=  
} 5d{Ggg{s  
pcTXTy 28  
@wJa33QT  
//打印回应的头信息 #|h8u`  
public void logResponseHead(HttpURLConnection con) pdqa)>$  
{ aMg f6veM  
for(int i=1;;i++) IMrOPwjc  
{ ?o5#Ve$-X  
String header=con.getHeaderFieldKey(i); -mo ' $1  
if(header!=null) %)ov,p |  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T\CQ  
Utility.log(header+" : "+con.getHeaderField(header)); @Hdg-f>y]  
else > 0)`uJ  
break; c;}n=7,>:L  
} `|?$; )  
} @7 HBXP  
\J&#C(pn  
:Zo2@8@7  
public void splitterStop() 5MU@g*gj,C  
{ *<QL[qyV  
bStop = true; 9sU,.T  
} l<_mag/j9o  
'6J$X-  
Eakjsk  
} H4A+Dg,  
3zF7V:XH  
S9+gVR8]C  
/* Dq 4}VkY  
**FileAccess.java J&1N8Wk)  
*//文件访问(定位,写) ~M1%,]  
package NetFox; 2]f.mq_PD  
import java.io.*; 2+cicBD  
lS*.?4zX  
3edK$B51;  
public class FileAccessI implements Serializable{ , )3+hnFY  
ZaindX{.1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G)|HFcE  
RandomAccessFile oSavedFile; jF85bb$  
long nPos; 5z]KkPQ  
=H?5fT^  
oD1=}  
public FileAccessI() throws IOException HOb\Hn|6jq  
{ Z i&X ,K~  
this("",0); d0E5;3tQ  
} ED&KJnquWJ  
W\Y 4%y}  
q`zR6  
public FileAccessI(String sName,long nPos) throws IOException S^=/}PT'  
{ 30`H Xv@  
oSavedFile = new RandomAccessFile(sName,"rw"); n:kxG  
this.nPos = nPos; ~36XJ  
oSavedFile.seek(nPos); S]@iS[|?  
} .sMi"gg  
[T|1Qq7  
)d Dmq  
public synchronized int write(byte[] b,int nStart,int nLen) (:]iHg3  
{ WT N!2b  
int n = -1; ,W;8!n0  
try{ /^ 7 9|$E  
oSavedFile.write(b,nStart,nLen); kIo?<=F8T  
n = nLen; e$I:[>  
} -q|M=6gOs  
catch(IOException e) Q-CVq_\3I  
{ 7@]hu^)rry  
e.printStackTrace (); 2mG?ve%m)  
} #2,L)E\G8e  
;yrcH+I$_  
WG4|Jf Y  
return n; &_gmQ;%t:  
} l%/,Ef*3  
$"1&!  
U?yXTMD  
} u{G6xuPWf  
'11hIu=:  
Hb4rpAeP  
/* (b!DJ;(O9  
**SiteInfoBean.java ePdzQsnVe  
*/ k Er7,c  
package NetFox; :D-vE7  
aW5~z^I  
]z NL+]1_  
public class SiteInfoBean { xSZw,  
I !~Omr@P  
0Z(b/fdS  
private String sSiteURL; //Site's URL VlvDodV  
private String sFilePath; //Saved File's Path ypVr"fWB  
private String sFileName; //Saved File's Name e@Y R/I8my  
private int nSplitter; //Count of Splited Downloading File ?Kf@/jv  
aS 2 Y6  
_: x$"i  
public SiteInfoBean() e&nw&9vo  
{//nSplitter的缺省值为5 VNPd L  
//default value of nSplitter is 5 _95tgJy  
this("","","",5); ${3OQG  
} L.[2l Q  
VtFh1FDI\  
r?*?iw2g  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d~%Rnic6*  
{ bN)?szh&Y  
sSiteURL= sURL; TA5M4r6  
sFilePath = sPath; lN" rhZ  
sFileName = sName; beoMLHp  
this.nSplitter = nSpiltter; so?1lG  
}o.ZCACYg  
c:5BQr '  
} G<DUy^$i  
7ac3N  
/8R1$7  
public String getSSiteURL() E u   
{ (reD  
return sSiteURL; u:|5jF  
} z /=v@@tj  
G#>X~qk()  
hBw~l?G  
public void setSSiteURL(String value) kPe9G  
{ hz|$3*q  
sSiteURL = value; hJ :+*46  
} m? hX=  
ap!<8N  
!)]3 @$#  
public String getSFilePath() A`Nb"N$H13  
{ up?8Pq*  
return sFilePath; *V}}3Degh  
} 7Ll(,i<,C  
?a}~yz#B(  
:OM>z4mQ  
public void setSFilePath(String value) \I=:,cz*,  
{  + h&V;  
sFilePath = value; .^,vK7  
} z?^p(UH  
%/y/,yd  
>v{m^|QqB  
public String getSFileName() Qt$Q/<8U  
{ ;I0/zeM%  
return sFileName; ?{'Q}%  
} CpXv?uU   
S3m+(N"&  
rX[R`,`>Z[  
public void setSFileName(String value) O%I'   
{ *`W82V  
sFileName = value; bH&H\ Mx_k  
} 6SwHl_2%  
zob-z=='  
w_ m  
public int getNSplitter() (g\'Zw5bk  
{ )yk LUse+  
return nSplitter; Sn]A0J_  
} W0|?R6|  
tg:x}n  
V/Tp&+Z.c  
public void setNSplitter(int nCount) WJ@,f%=<~  
{ 1<F/boF~  
nSplitter = nCount; lF<(yF5  
} i || /=ai  
} Y!H"LI  
11u qs S2  
wU3Q  
/* Q. >"@c[  
**Utility.java bCsQWsj^NW  
*/ s`{O-  
package NetFox; uf6{M_jXZ  
:;EzvRy  
PHoW|K_e  
public class Utility { $8Zw<aEJ  
Jad'8}0J  
4PdFq*A  
public Utility() 0Z\fK>yw  
{ 1/z1~:Il  
vDemY"wz  
S=o/n4@}  
} E5rNC/Ul$$  
pD{Li\LY  
//线程睡眠 1+]e?  
public static void sleep(int nSecond) SWu=n1J.?H  
{ 84k;d;  
try{ Y9C]-zEv  
Thread.sleep(nSecond); zr,jaR;  
} Cpr}*A   
catch(Exception e) QeK~A@|F&  
{ jooh`| `P  
e.printStackTrace (); X,p&S^  
} w/R^Vwq  
} 2c}kiqi{  
#M:W?&.  
//日志 ^E9@L ??  
public static void log(String sMsg) :Q%&:[2  
{ mU*GcWbc+  
System.err.println(sMsg); *I~F7Z]|  
} e= '3gzz  
a*=e 3nS  
,}NG@JID  
public static void log(int sMsg) k;%}%"EVZ  
{ sbRg=k&Ns  
System.err.println(sMsg); = zsXa=<  
} Ws=J)2q  
}  Z/64E^  
(T@ov~ @  
|(wx6H:  
/* k&Sg`'LG8  
**TestMethod.java 'h:4 Fzo<  
*/ _PuMZjGL  
package NetFox; 2 `#|;x^<  
%j=7e@   
X/@Gx 4  
public class TestMethod { pgI@[zp7  
sg3%n0Ms.W  
k07O.9>  
public TestMethod() !a0HF p$9  
{ ///xx/weblogic60b2_win.exe U_w)*)F  
try{ ':HV9]k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <)M?qkjb  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]^s4NXf+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); p 0-\G6  
fileFetch.start(); qoEOM%dAqV  
} (A1!)c  
catch(Exception e){e.printStackTrace ();} }ts?ZR^V,  
7UMsKE-  
iJ~p X\FKO  
} GU=h2LSi]  
1aSuRa  
$BG9<:p  
public static void main(String[] args) p t<84CP  
{ g|W~0A@D  
new TestMethod(); r8@:Ko= a  
} hj-M #a  
} E;%{hAD{  
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