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
  • 6935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
/* n<:d%&^n  
**SiteFileFetch.java N4H+_g|  
*/ T_x+sv=|X!  
package NetFox; @qPyrgy  
import java.io.*; NVJ&C]H6  
import java.net.*; Nr24[e G>d  
sk ?'^6Xh  
pTALhj#,  
public class SiteFileFetch extends Thread { Ww96|m  
nheU~jb  
q[7d7i/r6  
SiteInfoBean siteInfoBean = null; //文件信息Bean F[CT l3X  
long[] nStartPos; //开始位置 k9) u 3  
long[] nEndPos; //结束位置 i6md fp|k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Yxd{&47  
long nFileLength; //文件长度 'dc+M9u)_q  
boolean bFirst = true; //是否第一次取文件 Q*:h/Lhb&  
boolean bStop = false; //停止标志 f5aF6FBH  
File tmpFile; //文件下载的临时信息 6%kJDY.  
DataOutputStream output; //输出到文件的输出流 bqrJP3  
qggk:cN1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Dk`4bYK  
public SiteFileFetch(SiteInfoBean bean) throws IOException 43>9)t  
{ Pc(n@'m~  
siteInfoBean = bean; rMHQzQ0%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,MM>cOQ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )@,90Vhh  
if(tmpFile.exists ()) 1/2V.:bg  
{ ,|.8nk"  
bFirst = false; xIQ/$[&v  
read_nPos(); MkDK/K$s  
} eOehgU5x  
else )[^y t0%  
{ \- =^]]b=  
nStartPos = new long[bean.getNSplitter()]; sm;E2BR$ `  
nEndPos = new long[bean.getNSplitter()]; QtY hg$K3  
} b0YiQjS6>  
nuSN)}b<Q  
Ug7`ez4vw  
`z}vONXpAX  
} * -KJh_  
j/H>0^  
c6,s+^^  
public void run() l Io9,Ke  
{ A<SOT>m]  
//获得文件长度 d1V^2Hb?  
//分割文件 DD!MGf/  
//实例FileSplitterFetch {N!E5*$Tr  
//启动FileSplitterFetch线程 .Iw ur;/\  
//等待子线程返回 .?rbny  
try{ _ }E-~I>  
if(bFirst) StU  4{  
{ mDQEXMD  
nFileLength = getFileSize(); rGnI(m.  
if(nFileLength == -1) [1b6#I"x  
{ =.36y9Mfo  
System.err.println("File Length is not known!"); _F`$ d2  
} [ WV@w  
else if(nFileLength == -2) 0]T.Lh$3  
{ rQ~\~g[tP  
System.err.println("File is not access!"); )MWUS;O<  
} ME$2P!o  
else *jM_wwG  
{ YDQ:eebg(  
for(int i=0;i<nStartPos.length;i++) gA~20LSt  
{ K(nS$x1G  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); C4QeDvpI  
} >4n+PXRXX  
for(int i=0;i<nEndPos.length-1;i++) ;rB6u_5"I.  
{ gjj 93  
nEndPos = nStartPos[i+1]; `$s)X$W?  
} gq'>6vOj  
nEndPos[nEndPos.length-1] = nFileLength; 3 p/b  
} (O\U /daB  
} gi6g"~%@q1  
Deg!<[Nw  
aUH\Ee^M:R  
//启动子线程 YD&|1h  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F9(._ow[  
for(int i=0;i<nStartPos.length;i++) GX4QaT%  
{ Z_H?WGO  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @#RuSc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q6"uK  
nStartPos,nEndPos,i); gNShOu  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e`i7ah;  
fileSplitterFetch.start(); G' Blp  
} ,E\h!/X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OT%0{2c"]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]N*L7AVl  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E {tx/$f  
nEndPos = " + nFileLength); g;pR^D'M5C  
// fileSplitterFetch[nPos.length-1].start(); jY7=mAd  
+R-h ,$\=7  
wfgqgPo!v  
//等待子线程结束 ?4XnEDA m  
//int count = 0; %.mEBI=hs  
//是否结束while循环 W'a(oI  
boolean breakWhile = false; hd+]Ok7"  
l)4O .*  
M!1U@6n!=)  
while(!bStop) j'K38@M:MN  
{ ]' Y|N l  
write_nPos(); !p9)CjQ"  
Utility.sleep(500); I>PZYh'.T  
breakWhile = true; kv6Cp0uFg  
>F1G!#$0  
4&QUh+F  
for(int i=0;i<nStartPos.length;i++) Cyq?5\a  
{ |0`hE;Kt7  
if(!fileSplitterFetch.bDownOver) C5xag#Z1  
{ zuSq+px L@  
breakWhile = false; R}8XRe  
break; Wf#VA;d  
} _;56^1'T  
} $ a?  
if(breakWhile) e}'gvm  
break; {~SaRB2<'  
E<>*(x/\e  
A{# Nwd>  
//count++; $B;_Jo\|  
//if(count>4) NzQ9Z1Mxy  
// siteStop(); : [q0S@  
} nVE9^')8V  
MtS3p>4  
v2Bzx/F:  
System.err.println("文件下载结束!"); dBSbu=^$)  
}  v,=v  
catch(Exception e){e.printStackTrace ();} Lxv6!?v|  
} a5@z:i  
* z'8j  
"wAf. =F  
//获得文件长度 oH^(qZ8W  
public long getFileSize() %Y]=1BRk}  
{ (D<(6?  
int nFileLength = -1; NQfYxB1Yr:  
try{ /kgeV4]zR  
URL url = new URL(siteInfoBean.getSSiteURL()); hfqqQ!,l!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  ~*M$O&  
httpConnection.setRequestProperty("User-Agent","NetFox"); r> k-KdS  
"g>.{E5  
)"Q*G/+2Ie  
int responseCode=httpConnection.getResponseCode(); Wy4$*$  
if(responseCode>=400) c~0{s>  
{ oc7$H>ET1  
processErrorCode(responseCode); CS 8jA\  
return -2; //-2 represent access is error TX}T|ri  
} & $'z  
\8S ~c8Z~  
'$G"[ljr  
String sHeader; )[L^Dmd,  
0fm*`4Q  
gn8 |/ev  
for(int i=1;;i++) hoM|P8 }rh  
{ k1^\|   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LJFG0 W  
//Utility.log(in.readLine()); ]0c+/ \b&  
sHeader=httpConnection.getHeaderFieldKey(i); |F[=b'?  
if(sHeader!=null) \(~wZd  
{ !ErH~<f%K  
if(sHeader.equals("Content-Length")) 6KHN&P  
{ R\mR$\cS  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  x}TS  
break; p8}(kHUp(  
} QSw<%pcJE@  
} ht=P\E  
else ! }f1`/   
break; g13 rx%-  
} YO+{,$  
} JhHWu<  
catch(IOException e){e.printStackTrace ();} +JRF0T  
catch(Exception e){e.printStackTrace ();} 2 PqS%`XiS  
#3$\Iu  
@%/]Q<<q  
Utility.log(nFileLength); ~]HN9R^&  
yWDTjY/  
JL=U,Mr6  
return nFileLength; 7F^#o-@=J  
} B9R(&<4  
.zg8i_  
Cx<0 H  
//保存下载信息(文件指针位置) N8toxRu  
private void write_nPos() |re}6#TgcT  
{ \1"'E@+  
try{ O.`Jl%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); [XVEBA4GI  
output.writeInt(nStartPos.length); *&BnF\?m  
for(int i=0;i<nStartPos.length;i++) m: n` g1  
{ $ _j[2EU  
// output.writeLong(nPos); o*WY=  
output.writeLong(fileSplitterFetch.nStartPos); ({r*=wAP  
output.writeLong(fileSplitterFetch.nEndPos); v+ 7kU=  
} ?BA]7M(,4  
output.close(); fhPkEvJ  
} XfPFo6  
catch(IOException e){e.printStackTrace ();} Wj|alH9<  
catch(Exception e){e.printStackTrace ();} Zxr!:t7  
} Vd^g9  
%nN `|\  
{S/yL[S.  
//读取保存的下载信息(文件指针位置) j9Yb x#  
private void read_nPos() r={c,i  
{ `Z: R Ce^  
try{ aj8A8ma*}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5=Xy,hmnC  
int nCount = input.readInt(); ~h}Fi  
nStartPos = new long[nCount]; L`f^y;Y.  
nEndPos = new long[nCount]; [B@'kwD\l  
for(int i=0;i<nStartPos.length;i++) }En  
{ XU!2YO)t;!  
nStartPos = input.readLong(); :NJ_n6E  
nEndPos = input.readLong(); gE#>RM5D  
} )?+$x[f!*  
input.close(); Jk@]tAwoM  
} |4$M]Mf0  
catch(IOException e){e.printStackTrace ();} &'cL%.  
catch(Exception e){e.printStackTrace ();} theZ]5_C  
} JB!:JML  
QaUm1 i#  
s { #3r  
private void processErrorCode(int nErrorCode) S$KFf=0  
{ P96pm6H_;  
System.err.println("Error Code : " + nErrorCode); X%yO5c\l2  
} BA\/YW @  
oFOnjK"|F  
+"9hWb5  
//停止文件下载 n>@oBG)!  
public void siteStop() N0hE4t  
{ )`^p%k  
bStop = true; $kR N h6  
for(int i=0;i<nStartPos.length;i++) G\|,5HED  
fileSplitterFetch.splitterStop(); 8XbA'% o  
rG,5[/l  
$w"$r$K9K  
} 9x,RvWTb  
} ^C2\`jLMY  
//负责部分文件的抓取 ]HpA5q1ck  
**FileSplitterFetch.java Y*mbjyt[?X  
*/ (sVi\R  
package NetFox; LC1 (Xb f  
!i=nSqW  
=zwOq(Bh W  
import java.io.*; ^CwR!I.D}4  
import java.net.*; % ,+leKs  
2^?:&1:  
f/CuE%7BR  
public class FileSplitterFetch extends Thread { cwGbSW$t  
J\ e+}{  
9"g6C<  
String sURL; //File URL @&[T _l  
long nStartPos; //File Snippet Start Position 1S@vGq}  
long nEndPos; //File Snippet End Position o)'y.-@Q  
int nThreadID; //Thread's ID A*W) bZs.  
boolean bDownOver = false; //Downing is over j0@[Br%7  
boolean bStop = false; //Stop identical GR\5WypoJ  
FileAccessI fileAccessI = null; //File Access interface z=$jGL  
2t $j  
uc|45Zxt  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SNY~9:;]f  
{ ~o n(3|$  
this.sURL = sURL; bXS:x  
this.nStartPos = nStart; p !s}=wI `  
this.nEndPos = nEnd; c'*a{CV4P  
nThreadID = id; ZyEHzM{$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mFHH515  
} np~~mdmRK  
ek&kv#G  
LzYO$Ir:g  
public void run() *5xJv  
{ u ElAnrm  
while(nStartPos < nEndPos && !bStop) q4V7  
{ z $MV%F  
<8,cuX\  
@)K%2Y`  
try{ cV`E>w=D0  
URL url = new URL(sURL); %Q!`NCe+[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -j&Tc` j_  
httpConnection.setRequestProperty("User-Agent","NetFox"); dMrd_1  
String sProperty = "bytes="+nStartPos+"-"; Q[#vTB$f  
httpConnection.setRequestProperty("RANGE",sProperty);  f3UXCp  
Utility.log(sProperty); f  nI|  
$y b4xU  
 TT-h;'nJ  
InputStream input = httpConnection.getInputStream(); S(7ro]U9  
//logResponseHead(httpConnection); z)uuxNv[R  
}W ^: cp  
lSH6>0#B  
byte[] b = new byte[1024]; J/3_C6UZ  
int nRead; nJ" '  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t+Op@*#%  
{ +kFxi2L6  
nStartPos += fileAccessI.write(b,0,nRead); pAk/Qxl3eo  
//if(nThreadID == 1) cCR+D.F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N:9>dpP}O  
} c5mZG7-  
\o';"Q1H  
2ZQ}7`Y  
Utility.log("Thread " + nThreadID + " is over!"); [b$4Shx  
bDownOver = true; aj}(E +  
//nPos = fileAccessI.write (b,0,nRead); gR@C0  
} 5[Pr|AY  
catch(Exception e){e.printStackTrace ();} h;jIYxj  
} /6_|]ijc  
} Y \:0Ev  
bb d.  
WAn'kA  
//打印回应的头信息 [{X^c.8G)  
public void logResponseHead(HttpURLConnection con) (L`j0kPN  
{ (xq%  
for(int i=1;;i++) b?eu jxqg  
{ &Ni`e<mP  
String header=con.getHeaderFieldKey(i); ~gu3g^<0v  
if(header!=null) sUYxT>R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x\Y $+A,P  
Utility.log(header+" : "+con.getHeaderField(header)); "al `$%(  
else u_).f<mUdF  
break; )+Oujt  
} r `eU~7  
} 3su78et}  
P<K){V  
F9*g=  
public void splitterStop() %K]euEqs  
{ Lq>&d,F06)  
bStop = true; 4BwQA #zE  
} t5lO'Ll*Q]  
WlYs~(= 9  
O3CFme  
} d9n?v)<v  
f}D1|\7  
8KH\`5<  
/* |_ G )qp;  
**FileAccess.java WF\)fc#;_o  
*//文件访问(定位,写) {$ep7;'d  
package NetFox; #);[mW{F  
import java.io.*; dZ _zg<  
=LTmr1?  
=f(cH152T  
public class FileAccessI implements Serializable{ |T{C,"9y  
f>ZyI{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aTzjm`F0  
RandomAccessFile oSavedFile; %_Yx<wR%  
long nPos; 1bw{q.cmD  
jzK5-;b  
YSaJeU>@  
public FileAccessI() throws IOException !p1qJ [  
{ sN("+ sZ.n  
this("",0); [ 4;Ii  
} H}LS??P  
I=;+n-  
7n90f2"m  
public FileAccessI(String sName,long nPos) throws IOException nhN);R~o"1  
{ 7u[j/l,  
oSavedFile = new RandomAccessFile(sName,"rw"); s[gKc'  
this.nPos = nPos; KLX/O1B  
oSavedFile.seek(nPos); O+RP3ox"  
} jLJ1u/l>;  
%_UN<a  
#oJ5k8Wy  
public synchronized int write(byte[] b,int nStart,int nLen) X w.p  
{ p!/[K6u  
int n = -1; pZyQY+O  
try{ {Q<$Uo6V  
oSavedFile.write(b,nStart,nLen); y ?G_y  
n = nLen; 'q * Bdx  
} R<x'l=,D(  
catch(IOException e) .ZMW>U>  
{ G Xt4j  
e.printStackTrace (); L>Mpi$L  
} }Yv\0\~'W|  
Bb{!Yh].:A  
s`Cy a`  
return n; *z'yk*  
} 7E!7"2e a  
tb?YLxMV  
S^Au#1e   
} -{ u*qtp  
v_<2H' *Q  
+PK6-c\r  
/* _W3Y\cs,-  
**SiteInfoBean.java IcIOC8WC  
*/ t\v+ogbk)  
package NetFox; umLb+GbI4  
",>H(wJ8  
p h[\)  
public class SiteInfoBean { ?r_l8  
-A-tuyIsh"  
YwcPX`eg  
private String sSiteURL; //Site's URL hO[3Z ^X  
private String sFilePath; //Saved File's Path Gs2p5nL<  
private String sFileName; //Saved File's Name @/UfD ye  
private int nSplitter; //Count of Splited Downloading File (5^ZlOk3  
u-"c0@  
B}d.#G+_$x  
public SiteInfoBean() \M]-bw`  
{//nSplitter的缺省值为5 :c8n[+5  
//default value of nSplitter is 5 _7a'r</@  
this("","","",5); n-QJ;37\  
} OlD`uA  
0iEa[G3  
CVXytS?@x  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %i)B*9k  
{ ^6p'YYj"5  
sSiteURL= sURL; <Q<+4Y{R  
sFilePath = sPath; nT#JOmv  
sFileName = sName; ) uP\>vRy  
this.nSplitter = nSpiltter; TOLl@p]lU  
Eaad,VBtU  
ngi<v6i  
} /NF#+bx  
1px\K8  
b]gY~cbI8  
public String getSSiteURL() F=)eLE{W  
{ 6ri\>QrF  
return sSiteURL; 7.bN99{xPM  
} u}6v?!  
+pqM ^3t|y  
NHX>2-b  
public void setSSiteURL(String value) d`Q7"}uZ  
{ 9h(IUD{8  
sSiteURL = value; f"&Xr!b.h  
} b~7drf  
0'$p$K  
!F!3Q4  
public String getSFilePath() ``?6=mO  
{ G%TL/Z40  
return sFilePath; @{Py%  
} ;_<)JqUh  
'4;6u]d)2  
Uz8hANN0_  
public void setSFilePath(String value) Qu{c B^Ga*  
{ "PpjoM ~  
sFilePath = value; ST8!i`Q$  
} 'b:Ne,<  
$R{8z-,Q  
<xS=#  
public String getSFileName() UCqs}U8  
{ zREJ#r  
return sFileName; X`20f1c6q>  
} |k-XBp  
ACBQ3   
1"K*._K  
public void setSFileName(String value) _LfHs1g4  
{ Jme%  
sFileName = value; JE%A|R<Jl  
} ?p8k{N(1  
QV,E #(\5  
nx4P^P C  
public int getNSplitter() P0\eB S  
{ {^RG% &S  
return nSplitter; +p/1x'J  
} Nh)[r x  
ekzjF\!y  
4u:0n>nJ1  
public void setNSplitter(int nCount) #7z|mVzH  
{ q/6UK =  
nSplitter = nCount; K%,$ V,#  
} uzorLeu  
} dhR(_  
=hX[  
Z6=~1'<X  
/* &`:rp!Lc  
**Utility.java ~y\:iL//E  
*/ ^Qh-(u`  
package NetFox; K=kH%ZK  
, Fytk34  
Q(\ wx  
public class Utility { LC'F<MpM  
\K`jCsT  
q6[}ydV  
public Utility() I5pp "*u  
{  t9*=  
<lld*IH  
=l|>.\-  
} <NQyP{p  
{$TZ}z"DA  
//线程睡眠 E#h~V5Tf  
public static void sleep(int nSecond) .Dv=p B,u  
{ |>s v8/!  
try{ 44C+h    
Thread.sleep(nSecond); )W9_qmYd"  
} /| GH0L  
catch(Exception e) NV!4(_~  
{ Hhf72IX  
e.printStackTrace (); Wu{&;$  
} =WRO\lgv.  
} 3hJH(ToO  
Dt {')  
//日志 Y. TYc;  
public static void log(String sMsg) _bQL[eXd  
{ tBl#o ^  
System.err.println(sMsg); /VtlG+dLl  
} w4OW4J#  
2NR7V*A  
=K6c;  
public static void log(int sMsg) ta! V=U  
{ rUFFF'm\*a  
System.err.println(sMsg); "#XtDpGk  
} y"R("j $  
} ?cBO6^  
QeK{MF  
T 'i~_R6  
/* o4'v> b  
**TestMethod.java $n*%v85  
*/ &l!$Sw-u;  
package NetFox; "z/V%ZK~f  
6<76O~hNZ  
0o;~~\fq.  
public class TestMethod { 9%TT> 2#  
f=oeF]=I"  
#O6 EP#B  
public TestMethod() fIEw(k<*  
{ ///xx/weblogic60b2_win.exe C@)pmSQ  
try{ rys<-i(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /d]~ly @uI  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); # `58F.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); "8_,tYAH  
fileFetch.start(); .P%ym~S  
} zW)gC9_|m-  
catch(Exception e){e.printStackTrace ();} E.#6;HHzN  
Xv*}1PZH  
)[ w&C_>]  
} \Jf9npz3  
9mm2Vps;  
O99mic  
public static void main(String[] args) x.G"D(  
{ u !.DnKu  
new TestMethod(); ULTNhq R*n  
} /.2u.G  
} e7's)C>/'  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五