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http断点续传简单实现(java)

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/* ?zVcP=p@  
**SiteFileFetch.java &v9"lR=_k  
*/ C;9P6^Oz  
package NetFox; "j.Q*Hazg  
import java.io.*; j J54<.D  
import java.net.*; )0Vj\>  
c)q=il7ef  
-x?|[ +%  
public class SiteFileFetch extends Thread { Z+4Mo*#  
+?5Vuc%  
V P7LKfv  
SiteInfoBean siteInfoBean = null; //文件信息Bean vY[ u;VU  
long[] nStartPos; //开始位置 %f(4jQ0I  
long[] nEndPos; //结束位置 _ -,[U{  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 CurU6x1  
long nFileLength; //文件长度 ?Qts2kae#  
boolean bFirst = true; //是否第一次取文件 ;#*.@Or@Ah  
boolean bStop = false; //停止标志 h645;sb0  
File tmpFile; //文件下载的临时信息 L$jii  
DataOutputStream output; //输出到文件的输出流 d[E= HN  
}R:oWR  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `[ZA#8Ma  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5cl^:Ua  
{ V=+p8nE0  
siteInfoBean = bean; e"Z,!Q^-L  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); b'xBPTN  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .R S  
if(tmpFile.exists ()) 2Ns<lh   
{ $0]5b{i]  
bFirst = false; U<'$ \ P  
read_nPos(); Eh"Y<]$  
} ?pA_/wwp  
else B E#pHg  
{ "#{b)!EH  
nStartPos = new long[bean.getNSplitter()]; 3;!a'[W&p  
nEndPos = new long[bean.getNSplitter()]; /N@NT/.M<  
} mmMiA@0  
Yt r*"-  
MJK PpQ(,  
9mpQusM  
} [yRqSB  
[y<s]C6E  
<FN +  
public void run() ](IOn:MuDE  
{ h^J :k  
//获得文件长度 Exat_ L'?  
//分割文件 dE (d'*+a  
//实例FileSplitterFetch p%OVl[^jp  
//启动FileSplitterFetch线程 $=C ` V  
//等待子线程返回 g](&H$g  
try{ Af^9WJ  
if(bFirst) >q&e.-qL  
{ h@s i)5"  
nFileLength = getFileSize(); U/7jK40  
if(nFileLength == -1) u R!'v  
{ ux[13]yY  
System.err.println("File Length is not known!"); >PGsY[N  
} YT@H^=  
else if(nFileLength == -2) 0BOL0<Wq  
{ frWY8&W^H  
System.err.println("File is not access!"); $% W.=a'5  
} uLN.b339  
else 4XeO^#  
{ |J ^I8gx+  
for(int i=0;i<nStartPos.length;i++) nH[>Sff$  
{ HaOSFltf#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Z,F1n/7  
} r&XxF >  
for(int i=0;i<nEndPos.length-1;i++) zaE!=-U  
{ *mN8Qd  
nEndPos = nStartPos[i+1]; ;47=x1j i  
} TQ5kT?/{  
nEndPos[nEndPos.length-1] = nFileLength; 5%DHF-W)  
} Q%t _Epe  
} wJ7Fnj>u%  
vLCm,Bb2L  
4_4|2L3  
//启动子线程 G2J4N2hu  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'RR,b*Ql  
for(int i=0;i<nStartPos.length;i++) ?Y9VviC  
{ B^x}=Z4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), };cH5bYF  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w/7vXz<  
nStartPos,nEndPos,i); h:vI:V[/X  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qmnW  
fileSplitterFetch.start(); "VAbUs  
} UD5f+,_;  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /{Z<!7u;U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }oii|=,#^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /6p7 k  
nEndPos = " + nFileLength); X!]p8Q y  
// fileSplitterFetch[nPos.length-1].start(); ybgw#jv=  
m pM,&7}  
NW?h~2  
//等待子线程结束 XN'<H(G  
//int count = 0; cX48?srG  
//是否结束while循环 U9q6m3#$  
boolean breakWhile = false; Za1VJ5-  
-O[9{`i]  
W; ?'  
while(!bStop) kL%o9=R1  
{ w Yr M2X@  
write_nPos(); |B@\Nf7  
Utility.sleep(500); +/8KN  
breakWhile = true; Yo2n [  
~g;lVj,N'  
0S>U_#-  
for(int i=0;i<nStartPos.length;i++) XO4rrAYvW  
{ u[coWaPsZ  
if(!fileSplitterFetch.bDownOver) ldWr-  
{ .^uYr^( |[  
breakWhile = false; xA"7a  
break; ^g n7DiIPH  
} u_ym=N57`  
} -r6LndQs  
if(breakWhile) gz"I=9  
break; #pp6 ycy  
4B@L<Rl{\  
},tn  
//count++; [Ma d~;  
//if(count>4) \-)augq([  
// siteStop(); [+4--#&{  
} &V7{J9  
%!Ak]|[7  
P 4jg]g  
System.err.println("文件下载结束!"); uVV;"LVK~  
} ] _P!+5]<  
catch(Exception e){e.printStackTrace ();} 8w4cqr4m  
} WiclG8l  
8{J{)gF  
ai(J%"D"  
//获得文件长度 _#6ekl|%  
public long getFileSize() x-ShY&k  
{ s4Z5t$0|  
int nFileLength = -1; `$N AK  
try{ L\H,cimN  
URL url = new URL(siteInfoBean.getSSiteURL()); +;wu_CQu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /YH5s=  
httpConnection.setRequestProperty("User-Agent","NetFox"); ih/MW_t=m=  
=lqGt.x  
j`kw2(  
int responseCode=httpConnection.getResponseCode(); L;k9}HWpP  
if(responseCode>=400) 0 6S-3bis  
{ ` SO"F,  
processErrorCode(responseCode); 4F>?G{ci  
return -2; //-2 represent access is error <eG8xC  
} *%xmCP J  
sDvtk]4o-4  
4V0j1 k&'  
String sHeader; Z2u5n`K  
w6[uM%fHG  
#97w6,P+  
for(int i=1;;i++) f_GqJ7Gk]  
{ N_"mC^Vx  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H{3A6fb<  
//Utility.log(in.readLine()); :If1zB)  
sHeader=httpConnection.getHeaderFieldKey(i);  7ehs+GI  
if(sHeader!=null) F82_#|kpS  
{ Jd>"g9  
if(sHeader.equals("Content-Length")) 6?v)Hb}J%d  
{ s'|^6/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3mnq=.<(w  
break; ?1u2P$d  
} (lY< \l  
} Ju"*>66  
else #(G#O1+  
break; Dpa PRA)x  
} 4^mpQ.]lO  
} p%v+\T2r  
catch(IOException e){e.printStackTrace ();} Rv T>{G~  
catch(Exception e){e.printStackTrace ();} sOBy)vq?\  
wLf=a^c#  
GCTf/V\#  
Utility.log(nFileLength); 3G7Qo  
OK}+:Y  
J `8bh~7  
return nFileLength; ,U#$Qb 12  
} w1+xlM,,9  
lJloa'%v9  
iCYo?>  
//保存下载信息(文件指针位置) ^Pk-<b4}  
private void write_nPos() tOK lCc  
{ {$ghf"  
try{ >}~Pu| _ S  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b4$-?f?V  
output.writeInt(nStartPos.length); {b^JH2,  
for(int i=0;i<nStartPos.length;i++) D d$ SQ  
{ cDS6RO?  
// output.writeLong(nPos); )J"Lne*"  
output.writeLong(fileSplitterFetch.nStartPos); v~N8H+! d  
output.writeLong(fileSplitterFetch.nEndPos); ):lq}6J#  
} (&U8NeWZ  
output.close(); {Y! -]_ 5  
} k]=Yi;  
catch(IOException e){e.printStackTrace ();} $6a55~h|(  
catch(Exception e){e.printStackTrace ();} =sk]/64h``  
} }.x&}FqXE  
OJUH".o  
H *gF>1  
//读取保存的下载信息(文件指针位置) 7Xu.z9y  
private void read_nPos() )r#^{{6[v  
{ r1= :B'z  
try{ ]$'w8<D>t,  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1} {bHj  
int nCount = input.readInt(); ^y,% Tv>  
nStartPos = new long[nCount]; i-'rS/R  
nEndPos = new long[nCount]; `)[bu  
for(int i=0;i<nStartPos.length;i++) tU02t#8  
{ Wv]NFHe#  
nStartPos = input.readLong(); IG1+_-H:  
nEndPos = input.readLong(); ! `yg bI.  
} 3rEBG0cf]  
input.close(); ugtb`d{ Sl  
} u~,@Zg87  
catch(IOException e){e.printStackTrace ();} 5__8+R  
catch(Exception e){e.printStackTrace ();} <B*}W2\  
} %{*}KsS`p  
TlD)E  
9WaKsdf  
private void processErrorCode(int nErrorCode) |5 sI=?p&t  
{ (#WE9~Sru  
System.err.println("Error Code : " + nErrorCode); 1)8;9 Ba:  
} 6Hz45  
gQJy"f  
XAV|xlfm  
//停止文件下载 $:R"IqDG  
public void siteStop() \Ze"Hv  
{ `Tx1?]  
bStop = true; :bx q%D%|o  
for(int i=0;i<nStartPos.length;i++) LY%`O#i.  
fileSplitterFetch.splitterStop(); ` gIlS^Q  
M~Yho".  
o:<g Jzg  
} ,[rh7 _  
} `CP}1W>  
//负责部分文件的抓取 z}vgp\cuT  
**FileSplitterFetch.java CY&Z*JI"'B  
*/ P%8zxU;  
package NetFox; %,-oxeM1u  
^w eU\  
3[: |)i)  
import java.io.*; iEG`+h'  
import java.net.*; fdIk{o  
A`|OPi)  
8'Eu6H&$G  
public class FileSplitterFetch extends Thread { ZW$PJmz  
rAK}rNxI  
L`%v#R  
String sURL; //File URL )]"aa_20]  
long nStartPos; //File Snippet Start Position Zs _Jn  
long nEndPos; //File Snippet End Position I^pD=1Y]  
int nThreadID; //Thread's ID /jdq7CF  
boolean bDownOver = false; //Downing is over B1]dub9  
boolean bStop = false; //Stop identical `Z*k M VN  
FileAccessI fileAccessI = null; //File Access interface  hfpSxL  
D}1Z TX_  
!JtVp&?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x?0ZzB),  
{ H]5%"(h  
this.sURL = sURL; >}` q4U6$  
this.nStartPos = nStart; 9S ~!!7oj  
this.nEndPos = nEnd; )x1LOMe  
nThreadID = id; ln#Jb&u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DGMvYNKTj  
} %UuV^C  
XOQj?Q7)U  
d Ybb>rlu  
public void run() ^lCys  
{ ?Xscc mN  
while(nStartPos < nEndPos && !bStop) #!d@;= [\  
{ <(rf+Ou>I  
-I7"9}j3  
-,NiSh}A  
try{ 1s4+a^ &  
URL url = new URL(sURL); +;7Rz_.6f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4-@D`,3L  
httpConnection.setRequestProperty("User-Agent","NetFox"); Z `FqC  
String sProperty = "bytes="+nStartPos+"-"; m&xyw9a  
httpConnection.setRequestProperty("RANGE",sProperty); Ti`H?9t  
Utility.log(sProperty); ` V}e$  
[,s{/OM  
Gma)8X#  
InputStream input = httpConnection.getInputStream(); md_9bq/w  
//logResponseHead(httpConnection); x35(i  
=vx iqRm  
[ay~l%x  
byte[] b = new byte[1024]; }Wf\\  
int nRead; 1{B^RR.  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fj<#*2{]B  
{ "G\OKt'Z  
nStartPos += fileAccessI.write(b,0,nRead); |7Z7_YWs  
//if(nThreadID == 1) ?[>+'6  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CN6@g^)P  
} M#II,z>q  
2 fp\s5%J}  
L M  
Utility.log("Thread " + nThreadID + " is over!"); tmF->~|  
bDownOver = true; Mq!03q6  
//nPos = fileAccessI.write (b,0,nRead); A+d&aE }3V  
} _ F&BSu  
catch(Exception e){e.printStackTrace ();} f6x}M9xS%  
} ]J\tosTi  
} (Hqy^EOZ  
V3&_ST  
_idTsd:\  
//打印回应的头信息 fMaUIJ:Q9  
public void logResponseHead(HttpURLConnection con) ]YcM45xg  
{ Ie(vTP1Cj  
for(int i=1;;i++) VmM?KlC  
{ #8P9}WTno.  
String header=con.getHeaderFieldKey(i); d4h1#MK  
if(header!=null) n gA&PU  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); swv 1>52{  
Utility.log(header+" : "+con.getHeaderField(header)); M&Aeh8>uX  
else $i&u\iL  
break; "*O(3L.c-  
} epa)~/sA  
} .K>r ao'  
6XPf0Gl  
..RCR_DIp  
public void splitterStop() 1Wzm51RU  
{ .JIn(  
bStop = true; X PnN"Y"y  
} ,B ]kX/W  
y'ULhDgq^B  
O(BAw  
}  u!TVvc  
L=W8Q8hf  
[5$=G@ zf  
/* Q C?*O?~#  
**FileAccess.java dLQV>oF  
*//文件访问(定位,写) L1;IXCc=  
package NetFox; >D'Kt?L<]m  
import java.io.*; o.-rdP0P>  
ydFZ$W_}w  
N<V,5  
public class FileAccessI implements Serializable{ s,Uc cA@  
cTf/B=yMi  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6|*em4  
RandomAccessFile oSavedFile; J0@ ^h  
long nPos; yZJR7+  
wmh[yYWc  
:|i jCg+  
public FileAccessI() throws IOException umV5Y`  
{ S EdNH.|I  
this("",0); 7XLz Ewa  
} 6@_Vg~=S  
g:bw;6^ u  
^M60#gJ  
public FileAccessI(String sName,long nPos) throws IOException H2oAek(  
{ |pB[g> ~V  
oSavedFile = new RandomAccessFile(sName,"rw"); )r _zM~jI  
this.nPos = nPos; p:]kH  
oSavedFile.seek(nPos); "]|I;I"b  
} 6X{RcX]/  
.s7Cr0^k,|  
ghq#-N/t  
public synchronized int write(byte[] b,int nStart,int nLen) s UX%{|T_  
{ pq0F!XmU  
int n = -1; *gHGi(U(U  
try{ =sVB.P  
oSavedFile.write(b,nStart,nLen); F6 ?4E"d  
n = nLen; ,#Y>nP0  
} 595P04  
catch(IOException e) 'LY.7cW  
{ ^b-o  
e.printStackTrace (); -DgJkyt+<  
} gGl}~  
}Xv2I$J  
@?,iy?BSG  
return n; `8$gaA*  
} Z~O1$,Z  
Aa^%_5  
i^LLKx7M&  
} kI5`[\  
&_cMbFLBP  
\ UCOe  
/* !9+xKr99  
**SiteInfoBean.java '5j$wr zt  
*/ QAiont ,!  
package NetFox; -A}U^-'a}  
5AV5`<r.  
P~Cx#`#(V  
public class SiteInfoBean { AN ;SRl  
.H,v7L,~88  
uzA"+cV5  
private String sSiteURL; //Site's URL U2  0@B`<  
private String sFilePath; //Saved File's Path I@x^`^+l  
private String sFileName; //Saved File's Name l_ /q/8-l  
private int nSplitter; //Count of Splited Downloading File fz H$`X'M  
S+LE ASOr  
1^<R2x  
public SiteInfoBean() We]mm3M3  
{//nSplitter的缺省值为5 NijvFT$V1  
//default value of nSplitter is 5 8. 9TWsZ  
this("","","",5); A1`y_ Aj  
} =<nx [J  
7VWq8FH`  
5c*kgj:x  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kts#e:k@  
{ |7G +O+j  
sSiteURL= sURL; +AVYypql8K  
sFilePath = sPath; A1{ 7g<k6  
sFileName = sName; \bJ,8J1C  
this.nSplitter = nSpiltter; ^ ,`;x  
tz{W69k+  
Lyjt$i W%  
} /(#;(]  
gWcl@|I;\  
yEm[C(gZ  
public String getSSiteURL() ^_dYE]t  
{ d;GF<bz  
return sSiteURL; iY @MnnX  
} nqX)+{wAXe  
nSWW^ ;  
&6*X&]V!Z  
public void setSSiteURL(String value) M~ =Bln5  
{ pa1.+~)  
sSiteURL = value; ZMs$C3  
} $2l<X KT-  
iQryX(z  
hrsMAh!  
public String getSFilePath() SM3Q29XIw  
{ {<f_,Nlc  
return sFilePath; S%ULGX:@ga  
} ESdjDg$[u  
.GG6wL<$?  
)m . KV5K!  
public void setSFilePath(String value) Rlvb@aXgy  
{ }:NE  
sFilePath = value; 2, bo  
} :CH?,x^!@  
!?t#QD o  
dW hU o\>=  
public String getSFileName() >l|ao&z>bm  
{ ".Lwq_  
return sFileName; F/BB]gUB  
} 7g'jg7  
G&i<&.i  
~";GH20  
public void setSFileName(String value) m0XdIC]s  
{ cuenDw=eC  
sFileName = value; k+8K[ ?K-  
} 6.X| . N  
q/I':a[1  
3C8cvi[IS  
public int getNSplitter() JO*}\Es  
{ ,Jqi J?,4C  
return nSplitter; <5oG[1j  
} ;| (_;d  
[l;9](\8O  
>z&|<H%  
public void setNSplitter(int nCount) ,^]yU?eU  
{ >fCz,.L  
nSplitter = nCount; kNW}0CDgs  
} U Ke!zI  
} 3yT7;~vPj  
tPDd~fOk  
_T,X z_  
/* udCum4  
**Utility.java P.G`ED|K!Y  
*/ ,Mt/*^|  
package NetFox; ~zEBJgeyh  
x8L$T (^  
=u M2l  
public class Utility { }bwH(OOS  
Bismd21F6=  
e;QPn(  
public Utility() {<\[gm\X  
{ -)S(eqq1  
g=8}G$su{%  
)?@X{AN&  
} E038p]M!  
!3]}3jZ.  
//线程睡眠 !3Xu#^Xxj  
public static void sleep(int nSecond) AQCU\E  
{ &~ =q1?  
try{ 8T3j/ D<r  
Thread.sleep(nSecond); 3vs;ZBM  
} zq(R!a6  
catch(Exception e) .W>LsEk  
{ Dwvd  
e.printStackTrace (); pq<302uBQ  
} 3v oas  
} y _Mte  
xp+Z%0D  
//日志 (`z`ni  
public static void log(String sMsg) . 4$SNzv3V  
{ 5u(B]_r.  
System.err.println(sMsg); Ni"M.O);t  
} eVDO]5?  
4d\1W?i-  
:%&~/@B  
public static void log(int sMsg) 'IR2H{Q  
{ [QC|Kd^#  
System.err.println(sMsg); %XIPPEHU  
} ;QVX'?  
} i,77F!  
hrLPy V:  
~,199K#'  
/* U _QCe+  
**TestMethod.java I/F3%'O  
*/ dd$}FlT  
package NetFox; Vn4y^_H  
=!@5!  
h]|E,!H  
public class TestMethod { >P@JiR<@\n  
^o`;C\  
*b< a@  
public TestMethod() v/\in'H~  
{ ///xx/weblogic60b2_win.exe X- xN<S q  
try{ JYE[ 1M  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L.5 /wg  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8SJi~gV  
SiteFileFetch fileFetch = new SiteFileFetch(bean); j?5s/  
fileFetch.start(); C(t >ZR  
} }ioHSkCD  
catch(Exception e){e.printStackTrace ();} hB]\vA7  
znNJ?  
*G]zN"Y  
} I2U/ \  
"JHd F&  
rD7L==Ld  
public static void main(String[] args) ]z^*1^u^ig  
{ {w,g~ew `  
new TestMethod(); D7| =ev  
} WH@CH4WM  
} 9&FFp*'3  
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