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
  • 9990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
/* aT^ $'_ G  
**SiteFileFetch.java bU gg2iFS  
*/ 5Sl"1HL  
package NetFox; F2YBkwI  
import java.io.*; smCACQ$ (  
import java.net.*; Bo:epus}\  
q}i#XQU  
C b'|  
public class SiteFileFetch extends Thread { sm##owI  
$mxG-'x%K  
Pll%O@K  
SiteInfoBean siteInfoBean = null; //文件信息Bean GUL~k@:_k  
long[] nStartPos; //开始位置 2IJniS=[>  
long[] nEndPos; //结束位置 E+y_te^+b  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 PE{<' K\g  
long nFileLength; //文件长度 U*nB= =  
boolean bFirst = true; //是否第一次取文件 <xBL/e %  
boolean bStop = false; //停止标志 d8Vqmrc~  
File tmpFile; //文件下载的临时信息 G=qlE?j`j  
DataOutputStream output; //输出到文件的输出流 QXj#Brp  
4+8)0;<H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) WG,Il/  
public SiteFileFetch(SiteInfoBean bean) throws IOException Vu_oxL}  
{ xS,F DPA  
siteInfoBean = bean; mBIksts5h  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); gwNZ`_Q  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ,'C*?mms  
if(tmpFile.exists ()) e!Z}aOeE  
{ / 8O=3  
bFirst = false; t=lDN'\P  
read_nPos(); GX23c i  
} z81dm  
else h_-4Q"fb(  
{ H8g 6ZCU~  
nStartPos = new long[bean.getNSplitter()]; cZ%tJ(&\7X  
nEndPos = new long[bean.getNSplitter()]; v2gk1a &  
} nK< v  
xd `MEOY  
r5[pT(XT]  
0.m-}  
} zWPX  
ai d1eF  
=XYc2. t  
public void run() #P!<u Lc%  
{ P,zQl;  
//获得文件长度 X<_HQ  
//分割文件 ; Ows8  
//实例FileSplitterFetch z 3[J sE%  
//启动FileSplitterFetch线程 %qsl<_&  
//等待子线程返回 ?@in($67  
try{ jD<xpD  
if(bFirst) kE6/d,  
{ ,ye[TQ\,M  
nFileLength = getFileSize(); Yt=)=n  
if(nFileLength == -1) Dl~(NLM  
{ E"[p_ALdC  
System.err.println("File Length is not known!"); L!Tvz(_7f6  
} aZo}Ix:/  
else if(nFileLength == -2) W'Ew!]Q3  
{ ic}TiTK  
System.err.println("File is not access!"); #|+4`Gf^  
} W=g'Xu!|!2  
else Y>C0 5?>  
{ xC5Pv">  
for(int i=0;i<nStartPos.length;i++) 6.tA$#6HP  
{ oM>UIDCY_v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); e[Vk+Te7  
} bLWY Tj  
for(int i=0;i<nEndPos.length-1;i++) #?\(l%  
{ THy?Y  
nEndPos = nStartPos[i+1]; uDJ;GD[yc  
} E,ilJl\  
nEndPos[nEndPos.length-1] = nFileLength; 2::YR?  
} *MlEfmB(  
} K@:omT  
z3 ^_C`(F  
WqM| nX  
//启动子线程 _U LzA  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o,?G(  
for(int i=0;i<nStartPos.length;i++) 9 iJ$M!  
{ a6xo U;T  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C6F7,v62  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Odw'Ua  
nStartPos,nEndPos,i); Wj!+ E{y<r  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *pD|N  
fileSplitterFetch.start(); A4rMJ+!5  
} %A3m%&(m&%  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WB_BEh[>j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OXp N8Dh5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fD(r/~Vu  
nEndPos = " + nFileLength); x%k@&d;z  
// fileSplitterFetch[nPos.length-1].start(); P RUl-v  
\}4*}Lr  
D/"velV  
//等待子线程结束 S"?fa)~  
//int count = 0; rZ n@i  
//是否结束while循环 F_-xp1|  
boolean breakWhile = false; 8oI|Z=  
/;}%E  
J2 )h":2  
while(!bStop) ?%~^PHgZ|  
{ L#'XN H"  
write_nPos(); v,*C>u\3s  
Utility.sleep(500); g5pFr=NV  
breakWhile = true; :JX2GRL4  
.vy@uT,  
8!.V`|@lt  
for(int i=0;i<nStartPos.length;i++) |By[ev"Kh%  
{ %,~\,+NP  
if(!fileSplitterFetch.bDownOver) $mAC8a_Zu  
{ iFI+W<QR  
breakWhile = false; f@Jrbg  
break; ?M|1'`!c8  
} {irc~||4  
} &b^~0Z  
if(breakWhile) gjz-CY.hz  
break; _()1 "5{  
g-UCvY I  
hQY`7m>L  
//count++; U$OI]Dd9  
//if(count>4)  7 FY2a  
// siteStop(); K^@9\cl^  
} @.i#uMWF`  
OE0G*`m  
'@@!lV  
System.err.println("文件下载结束!"); $+n6V2^K)7  
} g=t7YQq_~  
catch(Exception e){e.printStackTrace ();} ^dk$6%0  
} u_+iH$zA  
u;t~ z  
Z|x|8 !D  
//获得文件长度 ,m]5j_< }  
public long getFileSize() Bf #cBI  
{ R3a}YwJFXF  
int nFileLength = -1; -@_v@]:  
try{ Q 318a0  
URL url = new URL(siteInfoBean.getSSiteURL()); e Bxm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E X'PRNB,  
httpConnection.setRequestProperty("User-Agent","NetFox"); a9p:k ]{  
! #! MTk  
6YNL4HE?  
int responseCode=httpConnection.getResponseCode(); qF `6l(  
if(responseCode>=400) =z"+)N  
{ jZkc yx  
processErrorCode(responseCode); NNbdP;=:u  
return -2; //-2 represent access is error %aw.o*@:  
} gELG/6l  
`?N0?;  
m }HaJ  
String sHeader;  P33xt~  
=c*l!."0  
z#o''  
for(int i=1;;i++) Y2 J-`o$5  
{ @>VVB{1@,]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jy2gR1~  
//Utility.log(in.readLine()); MA:5'n  
sHeader=httpConnection.getHeaderFieldKey(i); /; Bmh=  
if(sHeader!=null) UsFn!!+  
{ o.fqJfpj  
if(sHeader.equals("Content-Length")) m Rw0R{  
{ ~I+MuI[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s^eiym P  
break; =(7nl#o  
} !*"fWahv  
} T#3@r0M  
else 0&]1s  
break; zM=MFKhi ~  
} UWKgf? _  
} Rb0I7~Z%'d  
catch(IOException e){e.printStackTrace ();} 0]  
catch(Exception e){e.printStackTrace ();} oS..y($TI  
io+V4m  
1] ~w?)..'  
Utility.log(nFileLength); +Z|3[#W  
u>:(MARsR  
@ G)yz!H  
return nFileLength; ;H~<.QW  
} NvJ5[W  
1F`jptVQ\G  
Px=@Tw N,  
//保存下载信息(文件指针位置) HVHv,:bPo  
private void write_nPos() qJdlZW<  
{ )'U0n`=  
try{ A/'po_'uy  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ySmbX  
output.writeInt(nStartPos.length); .nrllVG%`  
for(int i=0;i<nStartPos.length;i++) v}Ju2}IK  
{ rjK`t_(=  
// output.writeLong(nPos); u7[}pf$}  
output.writeLong(fileSplitterFetch.nStartPos); 4_=2|2Wz[  
output.writeLong(fileSplitterFetch.nEndPos); w(6n  
} <8^x Mjc  
output.close(); k[ro[E  
} ,.W7Z~z  
catch(IOException e){e.printStackTrace ();} .M^[/!  
catch(Exception e){e.printStackTrace ();} 8\lh'8  
} ciS,  
=zyA~}M2  
BtC*]WB"_'  
//读取保存的下载信息(文件指针位置) >UaQ7CRo  
private void read_nPos() /gZyl|kdy  
{ vNv!fkl  
try{ !&rd#ZBn  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =,(TP  
int nCount = input.readInt(); MY@&^71i4  
nStartPos = new long[nCount]; a^p#M  
nEndPos = new long[nCount]; yk`qF'4]  
for(int i=0;i<nStartPos.length;i++) )e,O+w"  
{ )?$[iu7 s  
nStartPos = input.readLong(); Q# B0JT1  
nEndPos = input.readLong(); 6UeYZ g  
} R{H[< s+n  
input.close(); e(? w h   
} K@O^\  
catch(IOException e){e.printStackTrace ();} 7pyzPc#_  
catch(Exception e){e.printStackTrace ();} !=YKfzE  
} fu^W# "{  
BHUI1y5t  
:dSda,!z  
private void processErrorCode(int nErrorCode) ! ;t\lgMl  
{ 2]5{Xmmo9  
System.err.println("Error Code : " + nErrorCode); 8D*nU3O   
} jb.H[n,\  
 -BSdrP|  
Oo|PZ_P  
//停止文件下载 Ur(R[*2bx  
public void siteStop() r0XEB,}  
{ Db,"Gl  
bStop = true; -^xbd_'  
for(int i=0;i<nStartPos.length;i++) @x}"aJgl  
fileSplitterFetch.splitterStop(); kyJbV[o<#  
"Wwu Ty|  
DW. w=L|5R  
} RSp wU;o6z  
} .$18%jH#  
//负责部分文件的抓取 q<dG}aj  
**FileSplitterFetch.java *5%vU|9b  
*/ nF,F#V8l  
package NetFox; &<PIm  
P]43FPb  
V\;Xa0  
import java.io.*; e7RgA1  
import java.net.*; K*>%,mP$i  
VVas>/0qr  
5qb93E"C  
public class FileSplitterFetch extends Thread { $a M5jH<  
f4"UI-8;n  
]4l2jY  
String sURL; //File URL UTD_rQ  
long nStartPos; //File Snippet Start Position <q'l7 S  
long nEndPos; //File Snippet End Position {%R^8  
int nThreadID; //Thread's ID *q=T1JY  
boolean bDownOver = false; //Downing is over GJeG7xtJKl  
boolean bStop = false; //Stop identical m4mE7Wn.3  
FileAccessI fileAccessI = null; //File Access interface Q/+`9z+c  
Muo E~K2  
<\^0!v  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QqA=QTZ}  
{ v'W{+>.  
this.sURL = sURL; lP F326e  
this.nStartPos = nStart; i2,4:M)CV  
this.nEndPos = nEnd; 1RRE{]2v#  
nThreadID = id; VeYT[Us"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7IX8ck[D  
} v>8C}d^  
OETo?Wg1Z  
3p0v  
public void run() >h\y1IrAaG  
{ $ DL}jH^S  
while(nStartPos < nEndPos && !bStop) q[&Kr+)j  
{ _K^Q]V[nZ  
0bT j/0G?  
s1:Wrz?4  
try{ xyp{_ MZ  
URL url = new URL(sURL); Bf ut mI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oac)na:O#  
httpConnection.setRequestProperty("User-Agent","NetFox"); *F\wWg'!B  
String sProperty = "bytes="+nStartPos+"-"; n i#jAwkN5  
httpConnection.setRequestProperty("RANGE",sProperty); 6"Uu;Q  
Utility.log(sProperty); \^!;r9z=A  
J9Ao*IW~  
mZ+!8$1X  
InputStream input = httpConnection.getInputStream(); @ ^{`!>Vt  
//logResponseHead(httpConnection); Xs0)4U  
mUBy*.  
2q~ .,vpP  
byte[] b = new byte[1024]; PG&t~4QM`  
int nRead; XF!L.'zH  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JrzPDb`m  
{ $.PRav  
nStartPos += fileAccessI.write(b,0,nRead); RM;a]g*  
//if(nThreadID == 1) g#5R|| r  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }"D;?$R!  
} -?Cr&!*B  
G:AA>t  
5\Q Tm;  
Utility.log("Thread " + nThreadID + " is over!"); p*;!5;OUR  
bDownOver = true; 'nCVjO7o  
//nPos = fileAccessI.write (b,0,nRead); d^C@5Pd <  
} i,6OMB $  
catch(Exception e){e.printStackTrace ();} %K6veB{M  
} c1#0o) q*7  
} Xw?DN*`L  
nK>CPqB^(  
YX$(Sc3.6  
//打印回应的头信息 )~ ( *q  
public void logResponseHead(HttpURLConnection con) BEDkyz;:  
{ yf&g\ke  
for(int i=1;;i++) O^L]2BVC  
{ i2=- su  
String header=con.getHeaderFieldKey(i); pY31qhoZ.  
if(header!=null) d GUP|O  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0AQ azhm  
Utility.log(header+" : "+con.getHeaderField(header)); 6G8No-#y  
else  Rb6BY-/J  
break; Pb5yz-?  
} 9\Ii$Mp  
} [LYO'-g^F#  
F%w! I 9  
,lZ19B?WP  
public void splitterStop() eh86-tQI~(  
{ CMj =4e  
bStop = true; ,'8%'xit  
} roADC?@r  
%U\,IO`g  
lw@Yn>eza  
} 3&hR#;,"X  
zp}7p~#k^  
p<5]QV7st  
/* Q((&Q?Vi  
**FileAccess.java %*D=ni#(sT  
*//文件访问(定位,写) Qit&cnO  
package NetFox; `16'qc  
import java.io.*; 1j?P$%p  
Y~"tL(WfJl  
^ja]e%w#  
public class FileAccessI implements Serializable{ 2j s/>L0  
Ac:`xk<  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UqK.b}s  
RandomAccessFile oSavedFile; ]s\r3I]  
long nPos; CI W4E  
};Q}C0E  
*C_A(n5"V  
public FileAccessI() throws IOException 7:4c\C0  
{ 7`|'Om?'  
this("",0); |Z:yd}d  
} >Pw5! i\  
kckRHbeU  
,GSiSn  
public FileAccessI(String sName,long nPos) throws IOException +( LH!\{^  
{ #-L0.z(  
oSavedFile = new RandomAccessFile(sName,"rw"); &~:EmLgv  
this.nPos = nPos; de:@/-|  
oSavedFile.seek(nPos); #V k?  
} "laf:Ty1  
*AH `ob}  
4|x _C-@  
public synchronized int write(byte[] b,int nStart,int nLen) N:`_Vl  
{ OyO<A3  
int n = -1; /~,*DH$)  
try{ Ao K9=F}  
oSavedFile.write(b,nStart,nLen); $kUB%\`  
n = nLen; P(aBJ*((~  
} UC`h o%OBF  
catch(IOException e) KL$.E!d  
{ >|3Y+X  
e.printStackTrace (); ?!RbS#QV}  
} f^pBXz9&=  
um9&f~M  
]it. R-  
return n; 7y Cf3  
} hz/mNDE]  
U$y 9f  
G&oD;NY@/  
} m` 1dB%;?  
z^9oaoTl  
 [N,+mX  
/* 7$*E0  
**SiteInfoBean.java Tvv>9gS  
*/ r_+Vb*|Y  
package NetFox; =%U &$d|@G  
"51/,D  
6ALjM-t=V  
public class SiteInfoBean { B- @bU@H  
ag'hHFV  
@`[e1KQ  
private String sSiteURL; //Site's URL k$$SbStD  
private String sFilePath; //Saved File's Path L?ZSfm2<  
private String sFileName; //Saved File's Name kFjv'[Y1N  
private int nSplitter; //Count of Splited Downloading File !oH{=.w  
6 IvAs-%W  
-6)nQNj|  
public SiteInfoBean() 'Xik2PaO  
{//nSplitter的缺省值为5 h,\{s_b  
//default value of nSplitter is 5 -r *|N.5c  
this("","","",5); [8'?G5/n  
} -mO#HZIq  
q^xG%YdPz+  
"M/c0`>C!i  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ';R]`vWFe  
{ QGN+f)  
sSiteURL= sURL; 2TGND-(j  
sFilePath = sPath; -;cF)C--12  
sFileName = sName; 0MRWx%CR  
this.nSplitter = nSpiltter; !/G}vu  
V7WL Gy.,  
M6wH$!zRa  
} 4q .;\n  
_|e&zr  
"|JbdI]%P  
public String getSSiteURL() xoVd[c!   
{ p&I>xu8fl  
return sSiteURL; A.b^?k%I  
} )j2 #5`?"j  
B  W*8  
& %/p; ::A  
public void setSSiteURL(String value) K~#?Y,}O  
{ e6p3!)@P1  
sSiteURL = value; sqhMnDn[  
} M"*NV(".g  
d'(n/9K  
WWSycH ?[  
public String getSFilePath() tQ@7cjq8bA  
{ e (]]  
return sFilePath;  3?D, Wu  
} z#gebr~_\  
{N]WVp*R  
&en2t=a  
public void setSFilePath(String value) }"+"nf5h  
{ e/hCYoS1n  
sFilePath = value; ObM/~{rKx  
} {aA6b  
<,$*(dX)(  
!,ODczWvh  
public String getSFileName() l^I? @{W  
{ 7=G6ao7  
return sFileName; }Bv1fbD4U  
} o|>=< l  
="]lN  
|8E~C~d  
public void setSFileName(String value) r.)n>  
{ ]]y>d!  
sFileName = value; 1tTP;C l#  
} Foq3==*p  
`XF[A8@h  
XR",.3LD  
public int getNSplitter() Pfs_tu  
{ ,R=!ts[qi  
return nSplitter; -W6@[5c  
} sDs.da#*2  
ac\aH#J_nC  
^6# yL6E,~  
public void setNSplitter(int nCount) R@grY:h  
{ z~f;}`0  
nSplitter = nCount; xJw" 8V<  
} 64b AWHv  
} 1PxRj  
kKRu]0J~[  
. AA# G  
/* < e3] pM  
**Utility.java L [PqEN\i  
*/ )'jGf;du  
package NetFox; M#Z^8(  
E 1`g8Hk'  
KT<i%)t2  
public class Utility { ,X|FyO(p  
@[joM*U  
w}6~t\9D  
public Utility() \>4>sCC  
{ \X6q A-Ht  
uxdB}H,  
E`LaO  
} 8oU R/___  
De 3;}]wC  
//线程睡眠 c|:EMYS  
public static void sleep(int nSecond) aNM*=y`  
{ Q0`@=5?-  
try{ }+lK'6  
Thread.sleep(nSecond); \_u{ EB'b  
} xBc$qjV  
catch(Exception e) 2.JrLBhN  
{  %o/@0.w  
e.printStackTrace (); !!A(A^s  
} iLQO .'{U  
} dH0>lV  
Jv 5l   
//日志 aPe*@py3T  
public static void log(String sMsg) O:+y/c  
{ /(||9\;  
System.err.println(sMsg); ^xk4HF   
} ;s~xS*(C  
ZwxEcs+UM  
OWz{WV.  
public static void log(int sMsg) p\I3fI0i  
{ 44n41.Q]  
System.err.println(sMsg); U1 3Lsky%  
} A"DGn  
} -mO<(wfV>  
x-@?:P*  
StR)O))I  
/* T__@hfT  
**TestMethod.java {|%^'lS  
*/ P{s1NorKDh  
package NetFox; PRYm1Y  
Gyy4)dP  
^4JK4+!Zfq  
public class TestMethod { P5dD&  
ve a$G~[%6  
,]qc#KDq-1  
public TestMethod() ?l[#d7IB  
{ ///xx/weblogic60b2_win.exe rY &lx}  
try{ 6_8yQ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N1E9w:T`  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FME,W&_d  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {?w *n_T.  
fileFetch.start(); ,: z]15fX  
} VAheus  
catch(Exception e){e.printStackTrace ();} _;BNWH  
^eoW+OxH  
R/B/|x  
} }#g &l*P  
7!o#pt7  
D}{]5R  
public static void main(String[] args) bA6^R If?  
{ x`p908S^  
new TestMethod(); [N*S5^>1  
}  OvC@E]/+  
} MD;,O3Ge  
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