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http断点续传简单实现(java)

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/* #bnFR  
**SiteFileFetch.java mgS%YG  
*/ Hq=RtW2  
package NetFox; m|'TPy  
import java.io.*; m@OgT<E]_  
import java.net.*; N~SG=\rP;o  
DI+kO(S  
!IP[C?(nB  
public class SiteFileFetch extends Thread { Q&yfl  
/+%1Kq.hP  
-8g ;t3z  
SiteInfoBean siteInfoBean = null; //文件信息Bean ky,+xq  
long[] nStartPos; //开始位置 2uz<n}IV  
long[] nEndPos; //结束位置 o: TO[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 d!!5'/tmS  
long nFileLength; //文件长度 Dg \fjuK9  
boolean bFirst = true; //是否第一次取文件 "#(]{MY  
boolean bStop = false; //停止标志 iugTXZ(  
File tmpFile; //文件下载的临时信息 b bX2D/  
DataOutputStream output; //输出到文件的输出流 g {wDI7"<q  
9MVW~ V  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 87y$=eZ  
public SiteFileFetch(SiteInfoBean bean) throws IOException "h\{PoG  
{ wC;N*0Th  
siteInfoBean = bean; $f_Brc:n {  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); R/U"]Rc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -49OE*uF  
if(tmpFile.exists ()) ,Epg&)wC]  
{ J %URg=r  
bFirst = false; {V,rWg  
read_nPos(); ^2XoYgv  
} :43K)O"  
else !ZHPR:k|  
{ $GPenQ~},  
nStartPos = new long[bean.getNSplitter()]; (yn!~El3  
nEndPos = new long[bean.getNSplitter()]; ybcQ , e  
} Lr_+) l  
Ggsfr;m\`  
1P@&xcvS\  
yD$rls:v<  
} g.Z>9(>;Y  
PKty'}KF  
j'I$F1>Te  
public void run() Jx(%t<2  
{ mS6L6)] S  
//获得文件长度 kL{2az3"c  
//分割文件 R@u6mMX{N,  
//实例FileSplitterFetch esWgYAc3{  
//启动FileSplitterFetch线程 +UB+. 5P  
//等待子线程返回 +3!um  
try{ A7 E*w  
if(bFirst) :TxfkicN\  
{ 2>_6b>9]  
nFileLength = getFileSize(); [ wi "  
if(nFileLength == -1) z{7&=$  
{ zsc8Lw  
System.err.println("File Length is not known!"); #92 :h6  
} VrrCW/ o  
else if(nFileLength == -2) ]@)X3}"!  
{ K3M<%  
System.err.println("File is not access!"); -H#{[M8xX  
} TY],H=  
else Ul)2A  
{ gQCkoQi:j  
for(int i=0;i<nStartPos.length;i++) z+C>P4c-y&  
{ .yd{7Te  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =(3Qbb1i  
} FDkRfhK  
for(int i=0;i<nEndPos.length-1;i++) :w_Zr5H]  
{ /#GX4&z  
nEndPos = nStartPos[i+1]; -yy&q9  
} !LVWggk1  
nEndPos[nEndPos.length-1] = nFileLength; i-vhX4:bd  
} tK`sVsm>  
} =\eM -"r  
O&!+ni  
&&\ h%-Jc  
//启动子线程 }3!83~Qbx  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U"v(9m@  
for(int i=0;i<nStartPos.length;i++) 4/&Us  
{ zQMsS  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), be|k"s|6)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y{0`+/\`  
nStartPos,nEndPos,i); hc4<`W{  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >JkQ U e  
fileSplitterFetch.start();  Xai ,  
} f<= #WV  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %M2.h;9]*\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @F]6[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |"8Az0[!  
nEndPos = " + nFileLength); 3;zJ\a.+  
// fileSplitterFetch[nPos.length-1].start(); 7[rn ,8@  
Ek~Qp9B  
7hZCh,O  
//等待子线程结束 3ZGU?Z;R  
//int count = 0; S$HzuK\f  
//是否结束while循环 22"M#:r$  
boolean breakWhile = false; iNUisl  
|\TOSaZ  
OkGg4X|9  
while(!bStop) iA3d[%tBb  
{ -==@7*x!Z  
write_nPos(); DmEmv/N=  
Utility.sleep(500); p%EU,:I6  
breakWhile = true; *v)JX _  
;{ u{F L  
RIJ+]uir4  
for(int i=0;i<nStartPos.length;i++) S5*wUd*p#  
{ D|/Azy.[  
if(!fileSplitterFetch.bDownOver) :{pvA;f  
{ ck>|p09q'9  
breakWhile = false; {";5n7<<)  
break; mf=,6fx28  
} AR\>P  
} k!H;(B"s-  
if(breakWhile) pN6!IxN$  
break; $IX>o&S@|  
[wG?&l$.KB  
/Mb?dVwA  
//count++; IzF7W?k  
//if(count>4) &&4av*\I  
// siteStop(); ]`0(^)U &  
} N3g[,BE  
d|k6#f-E  
XL c&7  
System.err.println("文件下载结束!"); rV d(H  
} FiMP_ y*S  
catch(Exception e){e.printStackTrace ();} Un@B D}@\  
} ,LKY?=T$z  
.",E}3zn  
b2u_1P\  
//获得文件长度 u`dWU}m)  
public long getFileSize() ftq&<8  
{ A<2_V1  
int nFileLength = -1; ,u^i0uOg  
try{ <use+C2  
URL url = new URL(siteInfoBean.getSSiteURL()); Y,I0o{,g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L3lf28W  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6f,#O8]#5  
6 DqV1'  
,+<NP}Yg#G  
int responseCode=httpConnection.getResponseCode(); &:`T!n  
if(responseCode>=400) @;2,TY>Di  
{ Ar7vEa81  
processErrorCode(responseCode); 0^nnR7  
return -2; //-2 represent access is error !q=ej^(S  
} \_}Y4  
+Rn]6}5m\  
pE@Q (9`b{  
String sHeader; ]n1@!qa48  
qFp }+s  
unKTa*U^q  
for(int i=1;;i++) ]u  4  
{ :\9E%/aAD  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $HT {}^B  
//Utility.log(in.readLine()); O`5PX(J1&  
sHeader=httpConnection.getHeaderFieldKey(i); ;W,XP#{W  
if(sHeader!=null) Tm~a& p  
{ ~K]5`(KV  
if(sHeader.equals("Content-Length")) e}Cp;c]=  
{ P,lKa.  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3Xyu`zS&   
break; /=&HunaxI  
} =u W+>;]  
} QxG:NN;jW  
else XcB!9AIO  
break; ce-5XqzY@  
} "4"gHs  
} U|VF zpJ  
catch(IOException e){e.printStackTrace ();} @T[}] e  
catch(Exception e){e.printStackTrace ();} T#%r\f,l0  
!PJD+SrG  
{^zieP!  
Utility.log(nFileLength); 1eQa54n  
0)n#$d>  
'z7,)Q&8  
return nFileLength; }@%A@A{R  
} ':YFm  
!j[Oy r|  
GyQu?`  
//保存下载信息(文件指针位置) Jk=E"I6  
private void write_nPos() 'oSs5lW  
{ k)j, ~JH  
try{ F_0vh;Jo  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `%_yRJd|;  
output.writeInt(nStartPos.length); +EG?8L,z  
for(int i=0;i<nStartPos.length;i++) '&?cW#J?  
{ 6S7 =+>  
// output.writeLong(nPos); ?IRp3H  
output.writeLong(fileSplitterFetch.nStartPos); s8;/'?K  
output.writeLong(fileSplitterFetch.nEndPos); 'Vq_/g!?1  
} *9.4AW~]X  
output.close(); }jTCzqHW]  
} 1KwUp0% &  
catch(IOException e){e.printStackTrace ();} T= Q"| S]V  
catch(Exception e){e.printStackTrace ();}  _0^f  
} b.HfxYt(  
zIc%>?w  
#mu3`,9V  
//读取保存的下载信息(文件指针位置) Yzo_ZvL  
private void read_nPos() 'MZX"t  
{ u.W}{-+kp  
try{ anLSD/'4W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T^FeahA7;  
int nCount = input.readInt(); 1=Npq=d  
nStartPos = new long[nCount]; qy@v, a  
nEndPos = new long[nCount]; n:QFwwQ`Q;  
for(int i=0;i<nStartPos.length;i++) fCg"tckE  
{ eru2.(1  
nStartPos = input.readLong(); vb^/DMhz  
nEndPos = input.readLong(); tx0`#x  
} #r{`Iv ?nn  
input.close(); 2e~ud9,  
} Gp*U2LB  
catch(IOException e){e.printStackTrace ();} J* V@huF  
catch(Exception e){e.printStackTrace ();} ^\|Hz\"*  
} EPO*{bN7O  
TNgf96) y  
%K@s0uQ  
private void processErrorCode(int nErrorCode) "p,TYjT?R  
{ J*4byu|  
System.err.println("Error Code : " + nErrorCode); )1de<# qM  
} (H=7(  
6k14xPj  
m3o+iYkMD  
//停止文件下载 kFCjko  
public void siteStop() !a %6nBo  
{ i qLNX)  
bStop = true; (y^[k {#  
for(int i=0;i<nStartPos.length;i++) y9<]F6TT  
fileSplitterFetch.splitterStop(); T2Duz,  
c{7<z9U  
VE_%/Fs,  
} H~fX >6>  
} /m>%=_nz  
//负责部分文件的抓取 wXj!bh8\r  
**FileSplitterFetch.java E]Wnl\Be  
*/ AfQ?jKk&{'  
package NetFox; b \pjjb[  
z>n<+tso  
YG AB2`!U  
import java.io.*; >$^v@jf  
import java.net.*; Kterp%J?  
s> d /9 b  
{3V%  
public class FileSplitterFetch extends Thread { 8Xo`S<8VS  
`EFPY$9`D  
,ypD0Q   
String sURL; //File URL 6LVJ*sjSy  
long nStartPos; //File Snippet Start Position [xaglZ9HNo  
long nEndPos; //File Snippet End Position FrPpRe%!  
int nThreadID; //Thread's ID PxqRb  
boolean bDownOver = false; //Downing is over lQ t&K1m  
boolean bStop = false; //Stop identical u0 & aw  
FileAccessI fileAccessI = null; //File Access interface cwe@W PE2  
fi/[(RBG  
ss8de9T"'  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =%wwepz6  
{ 9lT6fW`v1Q  
this.sURL = sURL; xt{f+c@P  
this.nStartPos = nStart; k{{iF  
this.nEndPos = nEnd; ?AL;m.X-@  
nThreadID = id; C^dnkuA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t&GjW6]W  
} k@,&'imx  
 xr }jw  
g%Yw Dr=0t  
public void run() 3n\eCdV-b<  
{ :yLSLN  
while(nStartPos < nEndPos && !bStop) 8Gw0;Uu8D  
{ \|OW`7Q)k  
^CZ)!3qd1  
"q-,140_  
try{ z j[/~ I  
URL url = new URL(sURL); c(]NpH in  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @D<KG  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^p'iX4M  
String sProperty = "bytes="+nStartPos+"-"; %Q)3*L  
httpConnection.setRequestProperty("RANGE",sProperty); Z$8 X1(o  
Utility.log(sProperty); |VY+!  
[CCj5N1/  
3jH8pO^  
InputStream input = httpConnection.getInputStream(); d#?.G3YmK  
//logResponseHead(httpConnection); |.]:#)^X?  
W~TT`%[  
wEMh !jAbv  
byte[] b = new byte[1024]; p@/i e@DX  
int nRead; FIB 9W@oao  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G^Z SQ!  
{ "zT#*>U  
nStartPos += fileAccessI.write(b,0,nRead); E"EBj7<s  
//if(nThreadID == 1) eyx;8v cM  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4h|48</  
} =bVaB<!  
5CSihw/5  
]yTMWIx#  
Utility.log("Thread " + nThreadID + " is over!"); (sngq{*%%z  
bDownOver = true; kF09t5Lr  
//nPos = fileAccessI.write (b,0,nRead); Rf &~7h'+  
} {}vB# !  
catch(Exception e){e.printStackTrace ();} 3c#CEuu  
} z}Qt6na]-  
} ?qn0].  
o6FSSKM  
/Dn,;@ZwAi  
//打印回应的头信息 FfDe&/,/  
public void logResponseHead(HttpURLConnection con) YKjm_)8]w  
{ ;ew3^i.du  
for(int i=1;;i++) N8<Wm>GLX~  
{ '>GZB  
String header=con.getHeaderFieldKey(i); ews4qP  
if(header!=null) .?gpI Zv  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4FmT.P  
Utility.log(header+" : "+con.getHeaderField(header)); p8%/T>hK  
else 0?D`|x_  
break; \6UK:'5{  
} }CR@XD}[  
} ?a8 o.&`l  
cU,]^/0Y  
Us4ijR d  
public void splitterStop() xMk0Xf'_  
{ +Om(&\c(6  
bStop = true; B&l5yI b  
} {x3"/sF  
)G7")I J/X  
9-<EeV_/  
} X8TwMt  
e 1W9Z $m  
Q4gsOx P  
/* 3SRz14/W_R  
**FileAccess.java gm**9]k^{  
*//文件访问(定位,写) 83"Vh$&  
package NetFox; )qGw!^8  
import java.io.*; ogt<vng  
,a N8`M  
_z:7Dj#  
public class FileAccessI implements Serializable{ 95.m^~5  
\t LfB[S.5  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W'Wr8~{h  
RandomAccessFile oSavedFile; gO0X-fN8  
long nPos; gr\UI!]F  
7*bUy)UZ  
Ae&470  
public FileAccessI() throws IOException b' 1%g}  
{ $wL zaZL|  
this("",0); b?6-lYE>L  
} }O_kbPNw  
[P5+}@t  
h J*2q"  
public FileAccessI(String sName,long nPos) throws IOException by 'P}  
{ 0n5{Wr$  
oSavedFile = new RandomAccessFile(sName,"rw"); o!q3+Pp;}  
this.nPos = nPos; !f 7CN<  
oSavedFile.seek(nPos); dQD YN_  
} p 8,wr )  
[LDV*79Z  
.>4Zt'gCt  
public synchronized int write(byte[] b,int nStart,int nLen) [If%+mHdU  
{ Z`L-UQJ .  
int n = -1; 5)g6yV'  
try{ #r\,oXTm  
oSavedFile.write(b,nStart,nLen); [,A*nU$  
n = nLen; "bI'XaSv  
} aS ]bTYJ'  
catch(IOException e) ?P<8Zw  
{ QU4/hS;Ux  
e.printStackTrace (); xcBV,[E{  
} 84xA/BRW  
p.(8ekh  
jNKu5"HB  
return n; [PVem  
} Ce: 2Tw  
FW](GWp`:  
-4  ~(*  
} ulY8$jB  
`zD]*i(  
6Vr:?TI7  
/* N3J T[7  
**SiteInfoBean.java dMo456L  
*/  58S>B'  
package NetFox; #$vQT}  
z?ck*9SZX  
"eqNd"~  
public class SiteInfoBean { "pQFIV,  
;5i~McH# t  
x4b.^5"`:  
private String sSiteURL; //Site's URL %}T' 3  
private String sFilePath; //Saved File's Path 9$]I3k  
private String sFileName; //Saved File's Name ]+C;C  
private int nSplitter; //Count of Splited Downloading File 0A]+9@W;  
BKd03s=  
WA~PE` U  
public SiteInfoBean() ~353x%e'  
{//nSplitter的缺省值为5 oP[R?zN  
//default value of nSplitter is 5 $2tPqZ>  
this("","","",5); %E1_)^ ^  
} y(^hlX6gQ  
PWavq?SR  
6),U(e%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #*J+4a w3  
{ Qyh_o  
sSiteURL= sURL; /w5~ O:  
sFilePath = sPath; \=3fO(  
sFileName = sName; [I XX#^F  
this.nSplitter = nSpiltter; C rA7lu'  
wD*z >v$  
E~[v.3`  
} pn5A6 #  
y{Fq'w!ap  
ZvQ~K(3  
public String getSSiteURL() ;+86q"&n  
{ :6N'%LKK  
return sSiteURL; $|0?$U7!  
} k&<cFZU  
TbK;_pg  
0$saDmED  
public void setSSiteURL(String value) ZUkrJ'  
{ 4u!<3-3Zy  
sSiteURL = value; do-mkvk  
} KG2ij~v  
">-mZ'$#L  
Y6&B%t<bo  
public String getSFilePath() ('9LUFw\  
{ @i" ^b  
return sFilePath; TB oN8cB}  
} r.JY88"  
J)148/  
nVSuvq|S  
public void setSFilePath(String value) ?;q  
{ |=\w b^l+  
sFilePath = value; z?b[ 6DLV;  
} H@j D %  
b*AL,n?  
RhL!Z z  
public String getSFileName() 6+Y^A})(F-  
{ `S&$y4|Vs  
return sFileName; W5&;PkhQ6  
} r )pg9}+  
=7*k>]o  
MDyPwv\  
public void setSFileName(String value) =m+'orJ1  
{ 9rd7l6$R"  
sFileName = value; .b3c n  
} tB,1+I=   
*irYSTA$  
Dej2-Y  
public int getNSplitter() \Y?ByY  
{ _NkVi_UX  
return nSplitter; uyp|Xh,  
} O<:"Irq\qr  
xe=/T# %  
DbL=2  
public void setNSplitter(int nCount) xUKn  
{ bPe|/wp  
nSplitter = nCount; jTDaW8@L  
} 52zD!(   
} )`*=P}D  
;q3"XLV(T[  
l9zkx'xt.-  
/* Z2%ySO  
**Utility.java App9um3:  
*/ S<-e/`p=H  
package NetFox; O< \i{4}}  
>~D-\,d|f  
IPIas$  
public class Utility { | M|5Nc>W  
t:SME'~.P  
WZ3GI l  
public Utility() AWXBk+  
{ U^xz>:~  
Hp@nxtKxW  
7M#irCX  
} pow.@  
#cZ<[K q6  
//线程睡眠 K).Gj2 $  
public static void sleep(int nSecond) 2brxV'tk  
{ ;;3oWsil}  
try{ %]iDhXLr  
Thread.sleep(nSecond); Ag6^>xb^  
} k4AF .U`I  
catch(Exception e) {cW%i:  
{ { ]F };_  
e.printStackTrace (); 9A-=T>|of  
}  3g#  
} "s6\l~+9l  
Zdm7As]  
//日志 _UqE -+&  
public static void log(String sMsg) j\uh]8N3<  
{ -VO&#Mt5u  
System.err.println(sMsg); {Y(#<UDM  
} ^`MGlI}   
S%sD#0l  
5g$]ou  
public static void log(int sMsg) /jtU<uX  
{ ):c)$$dn  
System.err.println(sMsg); 4|]0%H~n6  
} z+k[HE^S  
} a9"1a'  
Ei Yj`P  
o-f;$]yp>  
/* ;Sqn w  
**TestMethod.java A0@E^bG  
*/ VsrYU@V  
package NetFox; &Oxf^x["]  
[ 1$p}x  
nc.(bb),  
public class TestMethod { YIc|0[ ]*|  
\?VNr2   
7SyysH<H  
public TestMethod() A.%MrgOOX  
{ ///xx/weblogic60b2_win.exe I\,m6 =q  
try{ z87_/(nu  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zBKfaQI,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /M3UK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~@Wg3'&  
fileFetch.start(); X;vfbF   
} 68 *~5]  
catch(Exception e){e.printStackTrace ();} T0Kjnzs  
dP7nR1GS  
! /qQ:k-.  
} 'WC> _ L  
us0{y7(p  
yt@;yd:OEk  
public static void main(String[] args) 6HK dBW$/  
{ XP |qY1  
new TestMethod(); eM1=r:jgE  
} 0YApaL+jt  
} 4L`<xX;:{  
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