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http断点续传简单实现(java)

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/* ,l$NJt   
**SiteFileFetch.java /i{tS`[F2a  
*/ % QPWw~}:  
package NetFox; X`fhln9N  
import java.io.*; dU ,)TKQ  
import java.net.*; JFG",09]  
qukjS#>+  
&0+x2e)7g  
public class SiteFileFetch extends Thread { ,pyQP^u-  
ShWHHU(QQ  
G{NSAaD[  
SiteInfoBean siteInfoBean = null; //文件信息Bean /lLov.  
long[] nStartPos; //开始位置 ` URSv,(  
long[] nEndPos; //结束位置 8"km_[JE e  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g>~cs_N@  
long nFileLength; //文件长度 (VYR!(17  
boolean bFirst = true; //是否第一次取文件 DO&+=o`"  
boolean bStop = false; //停止标志 Hs"% S  
File tmpFile; //文件下载的临时信息 NqJ<!q)  
DataOutputStream output; //输出到文件的输出流 ptV4s=G2  
L289'Gzg  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) U@.u-)oX  
public SiteFileFetch(SiteInfoBean bean) throws IOException /7k.r}6\R  
{ r]k*7PK  
siteInfoBean = bean; Kajkw>z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Hva2j<h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &l. x:eD  
if(tmpFile.exists ()) y$IaXr5L  
{ (O8,zqP9l  
bFirst = false; n}< ir!ZTO  
read_nPos(); 3yTQ  
} @72x`&|I?u  
else {q&@nm40  
{ @J-plJ4e  
nStartPos = new long[bean.getNSplitter()]; Qm.z@DwFM{  
nEndPos = new long[bean.getNSplitter()]; AH&9Nye8  
} >j50 ;</  
|Du,UY/  
>vlQ|/C  
bK3B3r#$  
} |}_gA  
sS, zzx<  
W1xf2=z`)T  
public void run() 2Sge  
{ ?VwK2w$&={  
//获得文件长度 f5@.^hi[  
//分割文件 p QluGIX0V  
//实例FileSplitterFetch ^DBD63 N"  
//启动FileSplitterFetch线程 L~*u4  
//等待子线程返回 !xkj30O(G  
try{ 'sj9[o@]  
if(bFirst) r2RBrZ@1  
{ C@%iQ]=  
nFileLength = getFileSize(); a*Rz<08  
if(nFileLength == -1) Ns'FH(:  
{ <z^SZ~G  
System.err.println("File Length is not known!"); z>6.[Z(T  
} c  Qld$  
else if(nFileLength == -2) 1'NhjL  
{ o g_Ri$x8  
System.err.println("File is not access!"); z{%oJ_  
} \WWG>OUh.U  
else z4CJn[m9  
{ YMi/uy  
for(int i=0;i<nStartPos.length;i++) T3=(`  
{ F4Rr26M  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #`/bQ~s  
} sNL+F  
for(int i=0;i<nEndPos.length-1;i++) f[x~)=  
{ s~L`53A  
nEndPos = nStartPos[i+1]; $( S*GF$S  
} y)P&]&"?  
nEndPos[nEndPos.length-1] = nFileLength; nt7|f,_J  
} ;:P7}v fz!  
} d>Un J)V}  
$nj\\,(g  
V]Sgx00;  
//启动子线程 >wA+[81[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vruD U#  
for(int i=0;i<nStartPos.length;i++) -(!uC +BZX  
{ 4 bn t=5]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *t^eNUA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RF:04d  
nStartPos,nEndPos,i); \UOm]z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h{I`7X  
fileSplitterFetch.start(); gt'*B5F(  
} a_Jb> }  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *m*`}9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wu,S\!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }7%9}2}Iw  
nEndPos = " + nFileLength); kL|\wci  
// fileSplitterFetch[nPos.length-1].start(); rR\;G2p)  
]a M-p@  
sa G8g  
//等待子线程结束 }"hW b(  
//int count = 0; hqL+_| DW  
//是否结束while循环 8yn4}`Nc@  
boolean breakWhile = false; /N>} 4Ay  
)#a7'Ba  
 7SaiS_{:  
while(!bStop) WVOoHH  
{ 0Q7MM6  
write_nPos(); [P{a_(  
Utility.sleep(500); )AI?x@  
breakWhile = true; 40u7fojg2  
!~)90Z!  
\0nlPXk?G  
for(int i=0;i<nStartPos.length;i++) h(nj,X+  
{ >zQOK-  
if(!fileSplitterFetch.bDownOver) RpYcD  
{ T<P0T<  
breakWhile = false; Bhe{L?}0  
break; fH[Wkif  
} )9B:Y;>)  
} FNC[59   
if(breakWhile) #ra*f~G  
break; L!,d"wuD  
2 L:$aZ  
NEw $q4  
//count++; GV5qdD(  
//if(count>4) a$}NW.  
// siteStop(); +p z}4M`  
} *jE;9^  
->h5T%sn  
h,t:]  
System.err.println("文件下载结束!"); QXs8:;T  
} @MOCug4  
catch(Exception e){e.printStackTrace ();} xz8G}Ku  
} FIS "Z(  
{rDq_^  
LL.x11 o3  
//获得文件长度 pw\P<9e=  
public long getFileSize() f0DK>L  
{ a~opE!|m  
int nFileLength = -1; BZ+;n |<r  
try{ 6Hk="$6K  
URL url = new URL(siteInfoBean.getSSiteURL()); ~>g+2]Bn>$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \x(^]/@  
httpConnection.setRequestProperty("User-Agent","NetFox"); hO \/  
s1 bU  
5$%XvM  
int responseCode=httpConnection.getResponseCode(); doR4nRl9  
if(responseCode>=400) '#q4Bc1  
{ L5f$TLw h;  
processErrorCode(responseCode); ^s-25 6iI  
return -2; //-2 represent access is error JhP\u3 QE  
} k"0;D-lTZ>  
0e16Ow6\!1  
DW>ES/B8$(  
String sHeader; [EOVw%R  
8I.VJ3Q  
JYJU&u  
for(int i=1;;i++) wXbsS)#/  
{ N}x9N.  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xb,T{.3@  
//Utility.log(in.readLine()); JNi=`X&A  
sHeader=httpConnection.getHeaderFieldKey(i); "}zt`3  
if(sHeader!=null) +rc SL8C  
{ C6]OAUXy:F  
if(sHeader.equals("Content-Length")) $gvr -~  
{ X{\jK]O  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S)7/0N79A  
break; :$ %>4+l  
} Qnt5HSSt  
} v@n_F  
else |##GIIv;i  
break; t,HFz6   
} .Y\EE;8%  
} qybxXK:  
catch(IOException e){e.printStackTrace ();} ^2C>L}  
catch(Exception e){e.printStackTrace ();} /iG7MC\`  
p!DP`Ouc3\  
4TZ cc|B5  
Utility.log(nFileLength); 8:dQ._#v  
q.W>4 k  
p$XKlg&  
return nFileLength; ?lKhzH.T  
}  prrT:Y  
nB] Ia?  
wxdyF&U n  
//保存下载信息(文件指针位置) 24B<[lSK  
private void write_nPos() iKAusWj  
{ WD.U"YI8y  
try{ !%[S49s  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ].mqxf  
output.writeInt(nStartPos.length); tTuX\;G  
for(int i=0;i<nStartPos.length;i++) =J/FJb  
{ {dzoEM[ 1s  
// output.writeLong(nPos); =;ICa~`C;  
output.writeLong(fileSplitterFetch.nStartPos); L'E^c,-x~  
output.writeLong(fileSplitterFetch.nEndPos); fYX<d%?7  
} >cgpajx*  
output.close(); yWb4Ify  
} rQr!R$t/[  
catch(IOException e){e.printStackTrace ();} q-_' W,  
catch(Exception e){e.printStackTrace ();} GBQn_(b9I  
} /tj$luls5  
;;#`#v  
tj5giQ3DG)  
//读取保存的下载信息(文件指针位置) z7T0u.4Ss  
private void read_nPos() r,NgG!zq<  
{ 6N" l{!  
try{ 3WUH~l{UJ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,:GN;sIXg  
int nCount = input.readInt(); *y]+dK&-  
nStartPos = new long[nCount]; LW:1/w&pv  
nEndPos = new long[nCount]; ^+/kr/  
for(int i=0;i<nStartPos.length;i++) %l !xkCKA  
{ {x@|VuL=  
nStartPos = input.readLong(); : ]II-$/8  
nEndPos = input.readLong(); Ed-M7#wY  
} D/ Dt   
input.close(); ,={t8lN  
} {' 5qv@3  
catch(IOException e){e.printStackTrace ();} wT_h!W  
catch(Exception e){e.printStackTrace ();} $kPHxD!"  
} a9Y5  
=.Tv)/ea  
lFq{O;q7}  
private void processErrorCode(int nErrorCode) |FNCXlgZ  
{ !#N\ b  
System.err.println("Error Code : " + nErrorCode); Nneo{j  
} go'j/4Tp  
DBgMC"_   
=RsXI&&vh  
//停止文件下载 >I'% !E;  
public void siteStop() [hh/1[   
{ l=={pb  
bStop = true; >)**khuP7  
for(int i=0;i<nStartPos.length;i++) EL D!{bMT  
fileSplitterFetch.splitterStop(); w0J|u'H  
#wR;|pN  
Zv!{{XO2;  
} GbZ;#^S  
} zT9JBMNE:  
//负责部分文件的抓取 j*R,m1e8  
**FileSplitterFetch.java K8[DZ)rO;Z  
*/ 1hmc,c  
package NetFox; %X1x4t]  
z`3( ,V  
(z7+|JE.  
import java.io.*; nJFg^s 1  
import java.net.*; B[o`k]]  
QlZ@ To  
tWPO]3hW  
public class FileSplitterFetch extends Thread { {D`T0qPT[  
r4XH =  
0L-!! c3  
String sURL; //File URL 5iX! lAFJ  
long nStartPos; //File Snippet Start Position cP>o+-)  
long nEndPos; //File Snippet End Position m$2<`C=  
int nThreadID; //Thread's ID MuI2?:~:*4  
boolean bDownOver = false; //Downing is over .*/Fucr  
boolean bStop = false; //Stop identical E6MA?Ax&=  
FileAccessI fileAccessI = null; //File Access interface TnH\O$  
SNpi=K!yn  
wdas1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3HC  
{ }}{Yw  
this.sURL = sURL; 1KE:[YQ1  
this.nStartPos = nStart; H)(jh  
this.nEndPos = nEnd; gP}+wbk  
nThreadID = id; rZ03x\2  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -ysn&d\rV  
} 7jG(<!,  
ROb\Rx m  
dK9Zg,DZL  
public void run() ]uh3R{a/  
{ LHYLC>J  
while(nStartPos < nEndPos && !bStop) \2v"YVWw  
{ nv/[I,nw  
Gh( A%x)  
;0%OB*lcgE  
try{  iThSt72  
URL url = new URL(sURL); 2I'~2o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kUl  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6g:|*w  
String sProperty = "bytes="+nStartPos+"-"; !q"cpL'4  
httpConnection.setRequestProperty("RANGE",sProperty); uaPx"  
Utility.log(sProperty); ^TdZ*($5  
/Lf6WMit  
n# 7Pr/*0  
InputStream input = httpConnection.getInputStream(); :#t*K6dz  
//logResponseHead(httpConnection); a[!%L d  
7(a2L&k^  
t0E51Ic@  
byte[] b = new byte[1024]; B4H!5b  
int nRead; !nf-}z e{  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t+Bf#:  
{ :!TI K1  
nStartPos += fileAccessI.write(b,0,nRead); M[]A2'fS  
//if(nThreadID == 1) 5"KlRuv%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E8[T   
} ]+ Ixi o  
\,G#<>S  
&2.u%[gO[q  
Utility.log("Thread " + nThreadID + " is over!"); (R}ii}&  
bDownOver = true; 2t#L:vY  
//nPos = fileAccessI.write (b,0,nRead); 9J-b6,  
} %VNlXHO.  
catch(Exception e){e.printStackTrace ();} # TkR  
} 3R$Z[D-  
} p s|)cW3`  
kGYTl,A{  
ro~+j}*   
//打印回应的头信息 .?W5{U  
public void logResponseHead(HttpURLConnection con) &:#h$`4  
{ =6nD sibf  
for(int i=1;;i++) 5jcte< 5I_  
{ S=|@L<O  
String header=con.getHeaderFieldKey(i); L@Nu/(pB=  
if(header!=null) ~aK?cP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qt e>r  
Utility.log(header+" : "+con.getHeaderField(header)); q OhO qV  
else {p<Zbm.  
break; ( )T[$.(  
} 15\Ph[6g  
} ^%T7.1'x  
&"Ux6mF-"  
6=GZLpv  
public void splitterStop() j7QX ,_Q  
{ ~p1EF;4#  
bStop = true; X@2-*so<  
} J;Rv ~<7  
Zo-$z8  
\E1U@6a  
} ,L> ar)B  
= "ts`>  
+a@GHx 4-  
/* }WLh8i?_  
**FileAccess.java d I'SwnR  
*//文件访问(定位,写) JH,/jR  
package NetFox; sY SLmUZ{  
import java.io.*; l:B;zi`)oB  
L:nXWz  
$^/0<i$   
public class FileAccessI implements Serializable{ LaFZ?7@|}  
22hSove.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 knp>m,w  
RandomAccessFile oSavedFile; cR7wx 0Aj  
long nPos; 6=_~ 0PcY  
l: |D,q  
1%[_`J;>Z  
public FileAccessI() throws IOException QbFHfA2Ij  
{ q<vf,D@{ !  
this("",0); I&yVx8aH}  
} 4<,|*hAT  
;F:fM!l=  
vsB*rP=  
public FileAccessI(String sName,long nPos) throws IOException ;i uQ?MR3  
{ >pyj]y^3  
oSavedFile = new RandomAccessFile(sName,"rw"); Njc%_&r  
this.nPos = nPos; dhPKHrS  
oSavedFile.seek(nPos); ]$-cMX  
} 8TV;Rtl  
ed 59B)?l  
:;;E<74e i  
public synchronized int write(byte[] b,int nStart,int nLen) DPgm%Xq9(!  
{ 6c4&VW  
int n = -1; x+5k <Xi}  
try{ SUCU P<G  
oSavedFile.write(b,nStart,nLen); Pz_Oe,{.I  
n = nLen; /lhz],w  
} }Rvm &?~O  
catch(IOException e) j1$8#/r;c  
{ RF}X ER  
e.printStackTrace (); j-@kW'K  
} < E|s\u  
C2U~=q>>  
gApoX0nrv  
return n; 0Wvq>R.(]7  
} #EO1`9f48x  
e9pOisZ;8  
G`h+l<  
} 'vV$]/wBF  
jF ^5}5U  
 }alj[)  
/* <~emx'F|  
**SiteInfoBean.java }3 m0AQ;K  
*/ I`RBj`IF  
package NetFox; vE, 37  
rnFM/GAy  
kfb/n)b'  
public class SiteInfoBean { ]DG?R68DQ  
}ucIH@U{  
9-1#( Y6S  
private String sSiteURL; //Site's URL \0;(VLN'U  
private String sFilePath; //Saved File's Path *O$CaAr\s  
private String sFileName; //Saved File's Name f|EUqu%E  
private int nSplitter; //Count of Splited Downloading File i%Z2wP.o  
;^u*hZN[Up  
q z&+=d@  
public SiteInfoBean() t G.(flW,  
{//nSplitter的缺省值为5 m4w ') r~  
//default value of nSplitter is 5 )emOKS  
this("","","",5); F!!N9VIC  
} o5o^TW{  
~,6b_W p/  
5AeQQU  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sd re#@n}  
{ l.)}t)my}  
sSiteURL= sURL; o}Cq.[G4k  
sFilePath = sPath; 4EP<tV  
sFileName = sName; 1$lh"fHU  
this.nSplitter = nSpiltter; 1nhtM  
5~ 'Ie<Y_  
*ZSdl 0e  
} :\~+#/=:  
~i;fDQ&!  
zdun,`6  
public String getSSiteURL() 3:/'n  
{ 9%)=`W  
return sSiteURL; y %8op:'  
} H5>hx {  
9.O8/0w7LV  
k,Qsk d-N]  
public void setSSiteURL(String value) :c[n\)U[aa  
{ ks;% *d  
sSiteURL = value; `\Ku]6J]5  
} .ae O}^  
&O\(;mFc  
XEM'}+d  
public String getSFilePath() +V862R4,o  
{ q~K(]Ya/  
return sFilePath; !G5a*8]  
} &F$:Q:* *  
d5I f"8`@  
B#%; Qc  
public void setSFilePath(String value) V_n<?9^4  
{ X26   
sFilePath = value; f3*?MXxb16  
} K!AAGj`  
/(C~~XP)  
7sNw  
public String getSFileName() qf)$$qi  
{ vC;]jJb:  
return sFileName; >XW*T5aUA  
} $K~LM8_CKy  
H( ^bC5'  
$3+PbYY  
public void setSFileName(String value) n";02?@F  
{ ,"}Rg1\4t  
sFileName = value; *~$~yM/~3U  
} { >{B`e`$  
_A_ A$N~9  
p\v Mc\  
public int getNSplitter() 2 -!L _W(  
{ Ft JjY@#  
return nSplitter; M&Y .;  
} 9~IQw#<  
0"k |H&  
3B0lb "e  
public void setNSplitter(int nCount) [t]X/O3<  
{ f2)XP$:  
nSplitter = nCount; i=FQGWAUu  
} `ejUs]SR  
} v`q\6i[-  
XkKC!  
(kBP(2V  
/* ?|;yVew  
**Utility.java 5-u=o )>  
*/ 72 TI  
package NetFox; ]Al;l*yw  
k5d\ w@G"~  
J<n+\F-s  
public class Utility { ;+"f  
LS>G4 ]  
wgeNs9L  
public Utility() pj|pcv^  
{ >:sUL<p  
tS# `.F~y  
5 +9 Ze9  
} ~89P[$6  
5__+_hO ;3  
//线程睡眠 X+8B!F  
public static void sleep(int nSecond) |tMn={  
{ /x@RNdKv  
try{ Vsq8H}K  
Thread.sleep(nSecond); DmqX"x%P  
} =V+I=rqo  
catch(Exception e) <g8K})P  
{ (AY9oei>  
e.printStackTrace (); ("7M b{  
} *mG`_9  
} /Poet%XvRx  
(3vHY`9  
//日志 I XA>`D  
public static void log(String sMsg) (n( fI f  
{ z;u> Yz+3  
System.err.println(sMsg); JeH;v0  
} t/i5,le  
C2e.2)y  
%n0;[sD0A  
public static void log(int sMsg) UnWW/]E  
{ T0HuqJty  
System.err.println(sMsg); m,LG=s  
} d4[(8} x$/  
} A!W0S  
!,$i6gm  
1nj(h g  
/* qf'm=efRyu  
**TestMethod.java uw\1b.r'B  
*/ {WN(&eax  
package NetFox; [ANuBNF  
w6|9|f/  
6x{<e4<n  
public class TestMethod { Tz&Y]#h_  
wy1X\PJjH  
?gGt2O1J  
public TestMethod() yQS+P8x&|]  
{ ///xx/weblogic60b2_win.exe <M?:  
try{ |Q~cX!;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w [>;a.$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5,"l0nrk  
SiteFileFetch fileFetch = new SiteFileFetch(bean); kW3E =pr  
fileFetch.start(); i y YJR  
} mbl]>JsQD  
catch(Exception e){e.printStackTrace ();} ,n,RFa  
I 1d0iU  
UAS@R`?cI  
} Y+%sBqo @  
< O*6 T%;  
zkM"cb13q/  
public static void main(String[] args) .uo.N   
{ C=Fzu&N}  
new TestMethod(); !4@G3Ae22  
} a[bBT@f  
} CLD-mx|?  
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