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http断点续传简单实现(java)

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/* 494"-F6  
**SiteFileFetch.java 7%) F]  
*/ ~4S@kYe{3K  
package NetFox; v_3r8My-  
import java.io.*; GD<xmuo  
import java.net.*; ?xu5/r<  
rH"&  
$TyV< G  
public class SiteFileFetch extends Thread { S 'S|k7Lp  
?B3   
`?+lM  
SiteInfoBean siteInfoBean = null; //文件信息Bean Nb~.6bsL  
long[] nStartPos; //开始位置 oswS<t{Z  
long[] nEndPos; //结束位置 I?}YS-2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 0"]N9N;/  
long nFileLength; //文件长度 ;^za/h>r  
boolean bFirst = true; //是否第一次取文件 M >#kfSF+  
boolean bStop = false; //停止标志 >0z(+}]3z  
File tmpFile; //文件下载的临时信息 e~w-v"'  
DataOutputStream output; //输出到文件的输出流 7SOi9JU_  
r)UtS4 7  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _yw]Cacr\  
public SiteFileFetch(SiteInfoBean bean) throws IOException Ea#wtow|-  
{ atR WKsY<  
siteInfoBean = bean; 2{:bv~*I0F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Hg(%g T  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %;$zR}  
if(tmpFile.exists ()) 8R<2I1xn2  
{ ;L (dmx?  
bFirst = false; @2ZE8O#I  
read_nPos(); ^}vLZA  
} ~jWG U-m  
else c@!%.# |y  
{ [+<lm 5t  
nStartPos = new long[bean.getNSplitter()]; f mu `o-  
nEndPos = new long[bean.getNSplitter()]; FMMQO,BU  
} ?UCK  
T<1* R>el  
{,61V;Bpm  
y ,e# e`  
} is @8x!c  
h8OmO5/H  
1 ;Bgtv$  
public void run() w9h`8pt  
{ C\#E1\d  
//获得文件长度 Wm_:1~  
//分割文件 !cS A|C  
//实例FileSplitterFetch C{AVV<  
//启动FileSplitterFetch线程 WfYu-TK *  
//等待子线程返回 *F7ksLH|q  
try{ 7~(|q2ib  
if(bFirst) l>p S23  
{  n aE;f)  
nFileLength = getFileSize(); sTeW4Hnp  
if(nFileLength == -1) !jZXh1g%  
{ ,?s3%<\2   
System.err.println("File Length is not known!"); $*a'[Qot#  
} 80=6B  
else if(nFileLength == -2) 7`AQn],  
{ }Fy~DsQ  
System.err.println("File is not access!"); |]FJfMX  
} X.TsOoy  
else N0TEVDsk  
{ (0Buo#I  
for(int i=0;i<nStartPos.length;i++) 92zo+bc  
{ Z#w@ /!"}T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); :Z rE/3_S  
} 8~Avg6,  
for(int i=0;i<nEndPos.length-1;i++) hI249gW9  
{ ^W}(]jL  
nEndPos = nStartPos[i+1]; #J&45  
} \H <k  
nEndPos[nEndPos.length-1] = nFileLength; Y v22,|:  
} &)Y26*(`  
}  5`];[M9  
6XU1w  
qRy<W  
//启动子线程  n *Y+y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; , H$1iJ?  
for(int i=0;i<nStartPos.length;i++) *htv:Sr  
{ VsLlPw{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aN n\URR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?8 dd^iX/  
nStartPos,nEndPos,i); ;.Dm?J0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v 809/c*  
fileSplitterFetch.start(); s'/b&Idf8  
} #bk[Zj&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i4"BN,NZ{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L{XNOf3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rO#WG}E<"  
nEndPos = " + nFileLength); ="X2AuK%1$  
// fileSplitterFetch[nPos.length-1].start(); Z*,Nt6;e  
+"8AmN4  
;Ohabbj*  
//等待子线程结束 =/_tQR~  
//int count = 0; #|\w\MJamP  
//是否结束while循环 Qe8F(k~k  
boolean breakWhile = false; C9+`sFau@  
g~,"C8-H  
=2-!ay:  
while(!bStop) `` !BE"yN  
{ |#uA(V  
write_nPos(); =Yd{PZ*fR  
Utility.sleep(500); kTJz .  
breakWhile = true; !{hC99q6  
vd0;33$L  
zB,Vi-)vH  
for(int i=0;i<nStartPos.length;i++) vE4ce  
{ 8cN[t.S  
if(!fileSplitterFetch.bDownOver) frsqnvm;+  
{ mBb;:-5  
breakWhile = false; Yfro^}f  
break; _wvSLu<q  
} w0`aW6t#  
} _T[7N|'O  
if(breakWhile) a g=,oYn  
break; Rwu y!F  
}V@ * :3w8  
h?cf)L  
//count++; fU?P__zU4  
//if(count>4) e15_$M;RW  
// siteStop(); Atdr|2  
} $?voQ&  
5G$sP,n  
QOb+6qy:3  
System.err.println("文件下载结束!"); R<"fcsU  
} f8Z[prfP  
catch(Exception e){e.printStackTrace ();} V_)G=#6Dy  
} (+M]C]  
J`uO~W"  
sR(or=ub~  
//获得文件长度 m6'VMW  
public long getFileSize() H83Gx;  
{ *OoM[wEY  
int nFileLength = -1; v$H=~m  
try{ >%x N?%  
URL url = new URL(siteInfoBean.getSSiteURL()); 2.xA' \M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nu'r `  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1=R6||8ws  
e|6kgj3/  
G6l:El&  
int responseCode=httpConnection.getResponseCode(); *<.{sx^Gk  
if(responseCode>=400) +`y{r^xD  
{ ihv=y\Jt  
processErrorCode(responseCode); ly!vbpE_  
return -2; //-2 represent access is error BYh F?  
} ao+lLCr  
!&8nwOG  
I-L52%E]  
String sHeader; 7FQ&LF46  
i. O670D  
A>C&`A=-  
for(int i=1;;i++) _zuaImJ0o  
{ `a$c6^a  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HUP~  
//Utility.log(in.readLine()); p,(gv])ie  
sHeader=httpConnection.getHeaderFieldKey(i); Nft~UggK  
if(sHeader!=null) 4Z'/dI`  
{ >M2~BDZ  
if(sHeader.equals("Content-Length")) -'q#u C  
{ Z4&,KrV  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #pe#(xoI  
break; [i"6\p&  
} #o>~@.S#:0  
} c8@zpkMj/  
else E:_m6 m  
break; lKtA.{(  
} 1KHFzx,  
} \3WF-!xe  
catch(IOException e){e.printStackTrace ();} .el&\Jt  
catch(Exception e){e.printStackTrace ();} :NHP,"  
pm)kocG  
w)nFH)f  
Utility.log(nFileLength); 5c 8tH=  
C i?BJ,  
Q sXy(w#F  
return nFileLength; 4@qHS0$  
} *VP-fyJp  
[Dzd39aKr  
t\\oG H  
//保存下载信息(文件指针位置) [WfigqY`b*  
private void write_nPos() PU& v{gn  
{ B4l*]K%  
try{ 26e.Hu  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `FJ2 ?  
output.writeInt(nStartPos.length); 7I#<w[l>k  
for(int i=0;i<nStartPos.length;i++) aa-{,X"MF  
{ MAv-`8@|  
// output.writeLong(nPos); >e'Hz(~'/  
output.writeLong(fileSplitterFetch.nStartPos); )o=ipm[  
output.writeLong(fileSplitterFetch.nEndPos); E]aQK.  
} vzXfJP  
output.close(); t)p . $  
} \f!j9O9S  
catch(IOException e){e.printStackTrace ();} 006 qj.  
catch(Exception e){e.printStackTrace ();} k=^~\$e  
} x>ZnQ6x~m]  
O4+a[82  
=%i~HDiy  
//读取保存的下载信息(文件指针位置) uQ(C,f[6p  
private void read_nPos() # $N)  
{ E"/r*C+T  
try{ dE_d.[!  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t.s;dlx[@  
int nCount = input.readInt(); *v}3So  
nStartPos = new long[nCount]; oe4r_EkYwW  
nEndPos = new long[nCount]; #;+ABV  
for(int i=0;i<nStartPos.length;i++) '5usPD  
{ ]Yw/}GKB  
nStartPos = input.readLong(); G`D~OI  
nEndPos = input.readLong(); [ Q@rW5,-  
} _aaQ1A`p  
input.close(); ~;QzV?%  
} (m~gG|n4  
catch(IOException e){e.printStackTrace ();} lihV! 1  
catch(Exception e){e.printStackTrace ();} fPpFAO  
} +";<Kd-  
pXE'5IIN  
!GAU?J;<#2  
private void processErrorCode(int nErrorCode) (O(X k+L  
{ Vm"{m/K0  
System.err.println("Error Code : " + nErrorCode); `mt x+C  
} I{8sLzA03S  
VoGyjGt&  
o-}q|tD$<  
//停止文件下载 =/Lwprj  
public void siteStop() L>ruNw'-K  
{ _u] S/X-  
bStop = true; ^&|KuI+ u  
for(int i=0;i<nStartPos.length;i++) c %f'rj  
fileSplitterFetch.splitterStop(); o4U[;.?c  
Z'<I Is:J  
R'z -#*[  
} ir?Y>  
} K^yZfpa8  
//负责部分文件的抓取 bC SgdK  
**FileSplitterFetch.java &F 3'tf?  
*/ + lNAog  
package NetFox; "J=A(w5   
-Uo"!o>x|  
wvnuE<o8  
import java.io.*; NDo>"in  
import java.net.*; FSNzBN  
LP{@r ic  
.wPu #*  
public class FileSplitterFetch extends Thread { k@Q>(`  
/ygC_,mx  
S [=l/3c  
String sURL; //File URL T1_qAz+  
long nStartPos; //File Snippet Start Position 9x]yu6  
long nEndPos; //File Snippet End Position wRCv?D`vV  
int nThreadID; //Thread's ID ? 3t]9z  
boolean bDownOver = false; //Downing is over 5;:964Et  
boolean bStop = false; //Stop identical (oG-h"^/  
FileAccessI fileAccessI = null; //File Access interface  TNj WZ  
x9qoS)@CM  
= a54  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `*ml/% \  
{ fnJ!~b*qo  
this.sURL = sURL; YsBOh{Ml  
this.nStartPos = nStart; WWtksi,  
this.nEndPos = nEnd; ([Da*Tk*  
nThreadID = id; h4,S /n  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2+'4m#@)  
} >$/PfyY7@#  
|WUm;o4E`U  
9`| ^cL*6  
public void run() g+zfa.wQ  
{ Afao Fn+  
while(nStartPos < nEndPos && !bStop) %AV[vr,  
{ ;#+Se,)  
(\A~SKEX  
iqAME%m  
try{ AZ'"Ua  
URL url = new URL(sURL); VYAz0H1-_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QZO9CLX 8k  
httpConnection.setRequestProperty("User-Agent","NetFox"); J.g4I|{  
String sProperty = "bytes="+nStartPos+"-"; qCUn. mI  
httpConnection.setRequestProperty("RANGE",sProperty); vbMt}bM(GD  
Utility.log(sProperty); Dxx`<=&g  
t)n}S;iD  
[Fo" MeH?R  
InputStream input = httpConnection.getInputStream(); 5a^b{=#Y  
//logResponseHead(httpConnection); w"/RI#7.  
24 L =v  
,f3Ck*M  
byte[] b = new byte[1024]; =(\xe| Q  
int nRead; ](tv`1A,Wd  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O~L/>Ya  
{ iI@m e=  
nStartPos += fileAccessI.write(b,0,nRead); {T(z@0Xu  
//if(nThreadID == 1)  0%OV3`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JQde I+  
} okSCM#&:[2  
jv5Os-  
jC3)^E@:"  
Utility.log("Thread " + nThreadID + " is over!"); 8r-'m%l  
bDownOver = true; <}z, !w8  
//nPos = fileAccessI.write (b,0,nRead); nLjc.Z\Bl  
} .`5BgX7W  
catch(Exception e){e.printStackTrace ();} 4.o[:5'  
} #CcWsI>+w>  
} :,*{,^2q:  
k,M %"FLQ  
|j> fsk~  
//打印回应的头信息 Xx;4  
public void logResponseHead(HttpURLConnection con) !^*-]p/z  
{ WY`hNT6M  
for(int i=1;;i++) -'F? |  
{ [(D^`K<b  
String header=con.getHeaderFieldKey(i); xJ[Xmre  
if(header!=null) %$3)xtS6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ix1[ $9  
Utility.log(header+" : "+con.getHeaderField(header)); /'WIgP  
else )<8f3;qd  
break; ^cz;UQX~}  
} cUPC8k.1  
} mO~A}/je  
O%R*1 P9  
"<LVA2v;  
public void splitterStop() |8<P%:*N  
{ 0//B+.#  
bStop = true; tc4"huG  
} TLC&@o :  
qt&zo5  
c=Y8R/G<  
} " +n\0j;  
@!MhVNS_<  
/'uFX,  
/* SPEDN}/^  
**FileAccess.java [ta3sEPjs  
*//文件访问(定位,写) @ApX43U(  
package NetFox; ),#hBB`ZA  
import java.io.*; @2eV^eO9  
tMQz'3,X  
I nCo[ 8SI  
public class FileAccessI implements Serializable{ LjOHlT'  
di,?`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xj+oV  
RandomAccessFile oSavedFile; L^Q q[>  
long nPos; XDM~H  
'<v_YxEn  
!/|^ )d^U  
public FileAccessI() throws IOException `kERM-@A  
{ xw5LPz;B  
this("",0); M!nwcxB!  
} leMcY6  
-g`3;1EV^  
Z-wvdw]$  
public FileAccessI(String sName,long nPos) throws IOException ZZJXd+Q}  
{ 0*-nVC1  
oSavedFile = new RandomAccessFile(sName,"rw"); RxZ#`$F  
this.nPos = nPos; ))z1T8  
oSavedFile.seek(nPos); 48  |u{  
} e_{!8u.+  
XnCrxj  
Js( "H  
public synchronized int write(byte[] b,int nStart,int nLen) ;?`l1:C5)  
{ ?5yj</W  
int n = -1; gY=Ry=w9  
try{ JMa[Ulz  
oSavedFile.write(b,nStart,nLen); rDvz2p"R  
n = nLen; ; D a[jFP  
} us,1:@a)a  
catch(IOException e) tm[e?+Iq  
{ y!;PBsU%Sx  
e.printStackTrace (); `4N{x.N  
} ~BJ~]~0P`  
['l.]k-b}  
Uq8=R)1<|d  
return n; @T6Z3Zj}  
} G>q16nS~KP  
5HAIKc  
Q|+g= |%^  
} <y30t[.E6  
{ylhh%t4hi  
Zagj1 OV|  
/* A7SE>e>  
**SiteInfoBean.java aTx*6;-PH  
*/ 3>I   
package NetFox; 8iDg2_l`G  
-< 0PBl  
Q:#Kt@W  
public class SiteInfoBean { V&>\U?q:  
<P"4Mk7`s  
;& PK6G  
private String sSiteURL; //Site's URL $^1L|KgXp  
private String sFilePath; //Saved File's Path  KOQ9K  
private String sFileName; //Saved File's Name DIU9Le  
private int nSplitter; //Count of Splited Downloading File eyLVu.  
+uY)MExs2  
7?O~3  
public SiteInfoBean() az=(6PX  
{//nSplitter的缺省值为5 U.[?1:v  
//default value of nSplitter is 5 lv* fK  
this("","","",5); V>2mz c  
} 0B;cQSH!q  
s, 8a1o  
G\U'_G>  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b35Z1sfD j  
{ SB3= 5"q  
sSiteURL= sURL; ?<#2raH-  
sFilePath = sPath; UOg4 E  
sFileName = sName; H%*< t}  
this.nSplitter = nSpiltter; P(Fd|).j$  
RRBokj)]  
+&p}iZp  
} TBzOz:k  
q~K KN /N  
=c>w  
public String getSSiteURL() guC7!P^  
{ 4p %=8G|  
return sSiteURL; rkW2_UTZE  
} !w[io;  
%!>~2=Q2*  
_Wjd`*  
public void setSSiteURL(String value) p FkqDU  
{ [AZN a  
sSiteURL = value; _IK@K 6V1  
} j9=QOq  
y@L-qO+{&  
8jnz;;|  
public String getSFilePath() NNt,J;  
{ c<8RRYs  
return sFilePath; JBsHr%!i  
} gD\  =  
t1I` n(]n  
-[I}"Glz:  
public void setSFilePath(String value) 06&:X^  
{ cN{-&\ 6L  
sFilePath = value; 1f"LAs`%  
} ZXf^HK  
$1CAfSgKw  
G(puC4 "&  
public String getSFileName() =H F||p@  
{ {iv!A=jld  
return sFileName; r#K;@wu2  
} |Q'l&Gt6  
`+!GoXI  
0wzq{~\{=_  
public void setSFileName(String value) S'I{'jP5  
{ +;}XWV  
sFileName = value; f8Xe%"<  
} Z]I[?$y  
jZm57{C#*?  
}a(x L'F  
public int getNSplitter() Y2DR oQ  
{ 2#n4t2 p  
return nSplitter; K,>D%mJ  
} e6n^l $'  
%EZG2JjO)  
?]fd g;?@  
public void setNSplitter(int nCount) !~{AF|2f  
{ 1!x-_h}  
nSplitter = nCount; dJhT}"x  
} EcA@bZ0  
} ?w}E/(r  
QPi]5z?  
:(,Eq?  
/* axl!zu*  
**Utility.java CL^MIcq?  
*/ FuZ7xM,  
package NetFox; 4s!rrDN  
# !?5^O  
0YsC@r47wL  
public class Utility { {-sy,EYcw  
Q1G?e,Q  
He4sP` &I  
public Utility() :eK;:pN  
{ 5N:THvh6o  
L`yyn/2>  
y7 I')}SC  
} QY<{S&k9  
vG'JMzAm  
//线程睡眠 CW(]6s u{  
public static void sleep(int nSecond) rNL*(PN}lO  
{ U!"+~d)  
try{ ,6Kx1 c  
Thread.sleep(nSecond); 9HOdtpQOV  
} $18|@\Znj  
catch(Exception e) Q?GmSeUi  
{ !s;+6Sy  
e.printStackTrace (); {*8'bNJ  
} ! K~PH  
} "YlN_ U  
U@<>2  
//日志 Ix,`lFbH  
public static void log(String sMsg) N#')Qz:P  
{ 8J:6uO c|  
System.err.println(sMsg); %Dg]n 4f  
} #Nt? 4T<  
C:n55BE9  
Q(-:)3g[aL  
public static void log(int sMsg) Vwp fkD`  
{ [@OXvdTV  
System.err.println(sMsg); (hefpqpi  
} #\G{2\R  
} zof>S>5>R7  
A f@IsCOJ  
]3_oT^$:  
/* ) MFa~/x  
**TestMethod.java ~n#rATbxf  
*/ W@w#A]  
package NetFox; o$4n D#P3  
Ed3 *fY  
bz[+g,e2oA  
public class TestMethod { +Io[o6*  
NTk"W!<Cl2  
{]~b^=qE$  
public TestMethod() uE~? 2G  
{ ///xx/weblogic60b2_win.exe j+:q:6=  
try{ %+iJpRK)7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8t!/O p ?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^tIi;7k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); "E;]?s9x  
fileFetch.start(); j_E$C.XU{g  
} T<\Q4Coth  
catch(Exception e){e.printStackTrace ();} 2G8f4vsC[  
o$>A;<  
" 1YARGu  
} tL1"Dt>  
u>j:8lhtV  
x68$?CD  
public static void main(String[] args) C8%Io l  
{ 83UIH0(  
new TestMethod(); d-g&TSGd  
} 2H8,&lY.p  
} xX`P-h>V`c  
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