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http断点续传简单实现(java)

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/* &pL.hM^  
**SiteFileFetch.java WT-BHB1  
*/ o|tq&&! <  
package NetFox; qHGwD20 ~  
import java.io.*; Mdj?;'Yv  
import java.net.*; L7gZ4Hu=`  
Rr9K1io$)  
(.CEEWj%{  
public class SiteFileFetch extends Thread { 86bRfW'  
gJ; *?Uq(  
@scy v@5)F  
SiteInfoBean siteInfoBean = null; //文件信息Bean $,mljJSQv  
long[] nStartPos; //开始位置 GH6HdZ  
long[] nEndPos; //结束位置 ?)Psf/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -w[j`}([P9  
long nFileLength; //文件长度 C\Y%FTS:  
boolean bFirst = true; //是否第一次取文件 h~!KNF*XW  
boolean bStop = false; //停止标志 >nqDUGnEo>  
File tmpFile; //文件下载的临时信息 v>p UVM  
DataOutputStream output; //输出到文件的输出流 &gP/<!#  
*an^ 0  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L,(H(GeX  
public SiteFileFetch(SiteInfoBean bean) throws IOException U)f;*{U  
{ d(=*@epjR  
siteInfoBean = bean; Y<x;-8)*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); #><P28m  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); B7*^rbI:X  
if(tmpFile.exists ()) \$g,Hgp/<  
{ [SJ)4e|)  
bFirst = false; i;CVgdQ8  
read_nPos(); h^H~q<R[T  
} v$P<:M M  
else RS8tE(  
{ mMz^I7$  
nStartPos = new long[bean.getNSplitter()]; 9AA_e ~y  
nEndPos = new long[bean.getNSplitter()]; )1EF7.|  
} $X>$)U'p&-  
*_qW;l7  
E#0_y4  
! H^,p$`[i  
} 3pV^Oe^9  
o_(@v2G`  
{\SJr:  
public void run() +9tm9<F8  
{ &=KNKE`  
//获得文件长度 U= Gw(  
//分割文件  MeP,8,n'  
//实例FileSplitterFetch I}Fv4wlZG  
//启动FileSplitterFetch线程 VssD  
//等待子线程返回 =SY`Xkj[  
try{ 7,.3'cCL^  
if(bFirst) 3 7F&s  
{ "%mu~&Ga  
nFileLength = getFileSize(); cnm*&1EzV  
if(nFileLength == -1) <r8sZrY  
{ GY%2EM(  
System.err.println("File Length is not known!"); 9On0om>  
} (]Pr[xB  
else if(nFileLength == -2) ++m^z` D  
{ lCX*Q{s22  
System.err.println("File is not access!"); LdPA`oI3j  
} 5Nt40)E}sN  
else 7V="/0a  
{ 4U;Zs3  
for(int i=0;i<nStartPos.length;i++) bW/^2B  
{ 2i4&*& A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ;%wY fq~P  
} &nRbI:R  
for(int i=0;i<nEndPos.length-1;i++) |([|F|"  
{ B5pWSS  
nEndPos = nStartPos[i+1]; 8+?|4'\`  
} >U.f`24  
nEndPos[nEndPos.length-1] = nFileLength; w]% |^:  
} U#X6KRZ~g  
} G2,9$8qE  
HQ7  
/}ADV2sF  
//启动子线程 A_ftf 7,  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FEF $4)ROv  
for(int i=0;i<nStartPos.length;i++) m?@0Pf}xa  
{ bMrR  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^w tr~D|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pE~>k:  
nStartPos,nEndPos,i); (Cc!Iw'0M  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `1hM3N.nO  
fileSplitterFetch.start(); #C`IfP./  
} @ uF$m/g  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x+%(z8wD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _[kZ:#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x =7qC#+)  
nEndPos = " + nFileLength); $3BH82  
// fileSplitterFetch[nPos.length-1].start(); p bT sn  
\nKpJ9!  
m,qMRcDF  
//等待子线程结束 `yvH0B -  
//int count = 0; x,+2k6Wn!  
//是否结束while循环 ` &E-  
boolean breakWhile = false; F4#^jat{  
^p2_p9  
1p DL()t  
while(!bStop) v!~ ;Q O  
{ mjI $z3  
write_nPos(); U7(t >/  
Utility.sleep(500); HXg#iP^tv  
breakWhile = true; VOa7qnh4:[  
#K4lnC2qz  
>}p'E9J?r  
for(int i=0;i<nStartPos.length;i++) 4Gsbcl{  
{ 5RUhrE   
if(!fileSplitterFetch.bDownOver) 5TB==Fj ?  
{ ;LhNz()b  
breakWhile = false; Vlka+$4!  
break; 4kr! Af  
} UD+r{s/%  
} f-'$tMs  
if(breakWhile) op|:XLR5  
break; 03$lgDQ  
SBbPO5^](  
RPh8n4&("  
//count++; p?#%G`dm  
//if(count>4) |nu)=Ag  
// siteStop(); `;R [*7  
} IuW5LS  
-IP3I  
H+O^el  
System.err.println("文件下载结束!"); "AayU  
} )2YZ [~3  
catch(Exception e){e.printStackTrace ();} \qA^3L~;5  
} G#f(oGn :  
+'!4kwTR  
:VvJx]  
//获得文件长度 (e~vrSk+)~  
public long getFileSize() o<f#Zi  
{ ~Bi{k'A9  
int nFileLength = -1; b~L8m4L  
try{ ss4<s 5:y  
URL url = new URL(siteInfoBean.getSSiteURL()); flr&+=1?D  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qUuvM  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^HUu"Kt  
B+pJWl8u  
Kd%>:E*  
int responseCode=httpConnection.getResponseCode(); D,<#pNO_  
if(responseCode>=400) `(dRb  
{ OZc.Rtgc  
processErrorCode(responseCode); [h=[@jiB  
return -2; //-2 represent access is error Q*c |!< &e  
}  M .J  
.o_?n.H'&  
eN?:3cP#l  
String sHeader; sO;]l"{<  
}8\"oA6  
=JK# "'  
for(int i=1;;i++) 8ba*:sb  
{ (+=TKI<=  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;xl_9Ht/  
//Utility.log(in.readLine()); noLb  
sHeader=httpConnection.getHeaderFieldKey(i); !P"=57d}"l  
if(sHeader!=null) zm9_[0  
{ ` g5S  
if(sHeader.equals("Content-Length")) mm@)uV<\  
{ zr1,A#BV  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uV'w0`$y  
break; <Ky6|&!  
} J@4,@+X  
} 9>1 $Jv3  
else `tjH#W`  
break; xSal=a;k  
} :87HXz6]jS  
} ,2y " \_  
catch(IOException e){e.printStackTrace ();} UB7H`)C}  
catch(Exception e){e.printStackTrace ();} I$#)k^Q  
UN"U#Si)  
IY=CTFQ8lm  
Utility.log(nFileLength); ~l@-gAyw  
jh*aD=y  
{+.ai8  
return nFileLength; RE?j)$y?`  
} 4t<l9Ilp  
AWqc?K@   
*\5o0~~8J  
//保存下载信息(文件指针位置) U}]uPvu  
private void write_nPos() ?xgrr7  
{ N`Q[OFe  
try{ 0 3/ <A^  
output = new DataOutputStream(new FileOutputStream(tmpFile)); nRL2Z5iO-  
output.writeInt(nStartPos.length); W2CQk  
for(int i=0;i<nStartPos.length;i++) %!_%%p,f  
{ $!-a)U,w$B  
// output.writeLong(nPos); _);;@T  
output.writeLong(fileSplitterFetch.nStartPos); n;5;D  
output.writeLong(fileSplitterFetch.nEndPos); `=B0NC.3  
} j& x=?jX  
output.close(); ]*Tnu98G}  
} =C[2"Y4JK0  
catch(IOException e){e.printStackTrace ();} ~LKX2Q:S  
catch(Exception e){e.printStackTrace ();} (H*d">`mz  
} y,OwO4+y\  
_H (:$=$Q  
@jp}WwC/  
//读取保存的下载信息(文件指针位置) eK]$8l|LI  
private void read_nPos() IUJRP  
{ lW8!_h"G`n  
try{ ]PI|Xl  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !KEnr`O2u  
int nCount = input.readInt(); xqA XfJ.  
nStartPos = new long[nCount]; ~1`ZPLVG  
nEndPos = new long[nCount]; FlPPz  
for(int i=0;i<nStartPos.length;i++) +l,6}tV9  
{ ?g5u#Q> !  
nStartPos = input.readLong(); ONkHHyT  
nEndPos = input.readLong(); M\f1]L|8d  
} 4X prVB  
input.close(); U'8ub(:&  
} \1p_6U7  
catch(IOException e){e.printStackTrace ();} =`oQcIkz  
catch(Exception e){e.printStackTrace ();} ,PyA$Z  
} \EC=#E(  
)Fo1[:_B '  
h"-}BjL  
private void processErrorCode(int nErrorCode) BW61WH?  
{ Owa]ax5  
System.err.println("Error Code : " + nErrorCode); 3?"JFfYU,'  
} NP {O  
\~YyY'J  
G\S>H  
//停止文件下载 {m&8Viq1  
public void siteStop() ezOZHY>|#  
{ w?+v+k\  
bStop = true; %j[DG_  
for(int i=0;i<nStartPos.length;i++) LT5rLdn  
fileSplitterFetch.splitterStop(); Yom,{;Bv  
MDo4{7  
hSvA dT]m  
} N]k(8K  
} ^uy2qO4Yw  
//负责部分文件的抓取 qU1^ K  
**FileSplitterFetch.java &Vtgh3I  
*/ oo:(GfO}  
package NetFox; y+C.2 ca  
8w[nY.#T  
_Q:739&  
import java.io.*; ;8G( l   
import java.net.*; LD~s@}yH>  
--~m{qmy  
PUdJ>U  
public class FileSplitterFetch extends Thread { NB z3j  
P0En&g+~  
x*9CK8o=  
String sURL; //File URL ZL-YoMHc+_  
long nStartPos; //File Snippet Start Position '|\et aD  
long nEndPos; //File Snippet End Position R`RLq1WA  
int nThreadID; //Thread's ID &y}nd 7o  
boolean bDownOver = false; //Downing is over g8_C|lVZi  
boolean bStop = false; //Stop identical E[FRx1^R9  
FileAccessI fileAccessI = null; //File Access interface f.o,VVYi  
a s{^~8B  
1xJc[q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \I"UW1)B  
{ 5nGDt~a  
this.sURL = sURL; ]vPa A  
this.nStartPos = nStart; Au6*hv3:  
this.nEndPos = nEnd; 4[S0~O{r  
nThreadID = id; g36\%L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]J t8]w  
} 4<['%7U_[  
yvgn}F{}  
jQKlJi2xu  
public void run() M# sDPT  
{ Y{ho[%  
while(nStartPos < nEndPos && !bStop) ^Fl6-|^~  
{ \qrSJ=}t  
R7L:U+*V"  
btfjmR<Tp  
try{ 8"M*,?.]  
URL url = new URL(sURL); K$H>/*&'~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `FP)-^A8  
httpConnection.setRequestProperty("User-Agent","NetFox"); Qe!Q $  
String sProperty = "bytes="+nStartPos+"-"; |vZ\tQ  
httpConnection.setRequestProperty("RANGE",sProperty); 7I6bZ;}d  
Utility.log(sProperty); :\*<EIk(  
,6zH;fi  
y=H^U.  
InputStream input = httpConnection.getInputStream(); !*0\Yi,6  
//logResponseHead(httpConnection); R?Dbv'lp>  
~ E) [!y  
K8`M~P.  
byte[] b = new byte[1024]; LWB"}#vt  
int nRead; G36}4  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U#O 6l-xe]  
{ (;V=A4F-D  
nStartPos += fileAccessI.write(b,0,nRead); *ay>MlcV2=  
//if(nThreadID == 1) FT1h\K|a  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b[^=GF>e  
} 8QeM6;^/5  
gzK"'4`  
)V^J^1  
Utility.log("Thread " + nThreadID + " is over!"); .qyk[O  
bDownOver = true; wp!<u %  
//nPos = fileAccessI.write (b,0,nRead); IX7|_ci  
} -$(,&qyk  
catch(Exception e){e.printStackTrace ();} ) #/@Jo2F  
} |kwkikGQS  
} qzVmsxBNP  
w$9aTL7  
) 0x* >;"o  
//打印回应的头信息 No)v&P%  
public void logResponseHead(HttpURLConnection con) *-timVlaE  
{ 74c1i  
for(int i=1;;i++) D!. r$i)  
{  W t&tu2  
String header=con.getHeaderFieldKey(i); BX|+"AeF  
if(header!=null) "+REv_:  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L%8>deE>;D  
Utility.log(header+" : "+con.getHeaderField(header)); p_$03q>oQ  
else X517PT8O  
break; ^@ GE1  
} e&C(IEZ/N;  
} v^aARIg  
OC zWP,  
um@RaU  
public void splitterStop() zaX!f ~;"  
{ A# W%ud4  
bStop = true; 71+J{XOC  
} K?_4|  
}N_9&I   
_/"m0/,  
} ?-,v0#  
k;p:P ?s5Y  
H1uNlPT  
/* _wWh7'u~G  
**FileAccess.java b;&J2:`  
*//文件访问(定位,写) <^&NA<2  
package NetFox; {m9OgR5U  
import java.io.*; &0O1tM*v  
5Qp5JMK  
`zHtfox!  
public class FileAccessI implements Serializable{ eR(PY{  
slEsSR'J]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uG\ +`[-{0  
RandomAccessFile oSavedFile; E+$vIYq:W  
long nPos; x.r~e)x=  
t;9f7~  
[R j=k)aBm  
public FileAccessI() throws IOException 3LZ0EYVL  
{ D"F5-s7  
this("",0); jxL5L[  
} Ys10r-kDS  
\oPW  
s> JmLtT  
public FileAccessI(String sName,long nPos) throws IOException VdR5ZP  
{ CTt3W>'=+  
oSavedFile = new RandomAccessFile(sName,"rw"); 9hI4',(rE  
this.nPos = nPos; o}p6qB=;1  
oSavedFile.seek(nPos); YJ]]6 K+  
} 3OV#H%  
xW{_c[oA  
^;B vd!  
public synchronized int write(byte[] b,int nStart,int nLen) 9)sGnD;  
{ w%cd $"EH  
int n = -1; #;U_ L`q  
try{ 5AR\'||u  
oSavedFile.write(b,nStart,nLen); 65RWaz;|  
n = nLen; MpM-xz~  
} "A^9WhUpJ  
catch(IOException e) Tn[DF9;?  
{ qFmvc  
e.printStackTrace (); |jW82L+!N%  
} -san%H'  
7t\W{y  
h\KQ{-Bl  
return n; i% k`/X;  
} 3|%Q{U  
tv)x(MX  
v\:>} <gc  
} >Vc_.dR)E  
:L`  
KYVB=14  
/* DY?`Y%"  
**SiteInfoBean.java ]j0v.[SX  
*/ I ms?^`N  
package NetFox; bT>% *  
8QDRlF:;<  
~=P&wBnJ  
public class SiteInfoBean { j& f-yc'i-  
 m2%uGqz  
N(Us9  
private String sSiteURL; //Site's URL 5xP\6Nx6&5  
private String sFilePath; //Saved File's Path M)6_Ta l  
private String sFileName; //Saved File's Name ,T_HE3K  
private int nSplitter; //Count of Splited Downloading File =35^k-VS  
VB*$lx X  
zl46E~"]x  
public SiteInfoBean() y[S 5  
{//nSplitter的缺省值为5 UDV,co  
//default value of nSplitter is 5 nCEt*~t9VE  
this("","","",5); FJo N"X  
} It!%/Y5  
=0`"T!1  
]7v-qd  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _h7!  
{ +Tde#T&[  
sSiteURL= sURL; BBnbXhxZ  
sFilePath = sPath; * 4G J<  
sFileName = sName; |h(!CFR  
this.nSplitter = nSpiltter; 7Q} P}9n  
w``t"v4  
yInW?3  
} BqK|4-Pf  
k}l5v)m  
e{.2*>pH  
public String getSSiteURL() S1wt>}w0$  
{ Nqp%Z7G  
return sSiteURL; p0? X R  
} =&xamA)  
d~uK/R-KD  
-ZH]i}$  
public void setSSiteURL(String value) U/Z!c\r  
{ jE2k\\<a  
sSiteURL = value; |HI =ykfI  
} {w}PV5<  
q .nsGbl  
[3;J,P=&  
public String getSFilePath() m!a<\0^  
{ %FLz}QW*  
return sFilePath; W}+Q!T=  
} SQWwxFJ  
EU TTeFp  
[oKc<o7)~"  
public void setSFilePath(String value) @~'c(+<3  
{ 8Z:NT_Ss  
sFilePath = value; ()v[@"J  
} {%^q8l4j  
KWCA9.w4q  
$}2m%$vJO  
public String getSFileName() u2y?WcMv  
{ S%-L!V ,  
return sFileName; 6cVaO@/(  
} e(x1w&8dB  
c^}gJ  
yAG4W[  
public void setSFileName(String value) h" Yi'  
{ DY^q_+[V  
sFileName = value; yp wVzCUG  
} A5z`_b4f  
K=M5d^K<E  
g&O%qX-  
public int getNSplitter() 5R?iTB1,  
{ ^4x(a&  
return nSplitter; *bDuRr?v9  
} }:5r#Cd  
=B4mi.;@i  
Xl;u  
public void setNSplitter(int nCount) %A`f>v.7 c  
{ f8L  
nSplitter = nCount; [{ K$sd  
} F=Z|Ji#  
} s{x2RDAt  
qxG @Zd  
m[!t7e  
/* 0Q_AF`"  
**Utility.java ;:vbOG#aSN  
*/ ^O6PZm5J}  
package NetFox; Y b]eWLv  
*5hg}[n2  
!h}x,=`z/  
public class Utility { *J=`"^BO  
52q@&')D4M  
Q9q:HGXxv  
public Utility() 3%|LMX]M5_  
{ _OZrH(8  
' ]l,  
~A}"s-Kq5  
} 0diQfu)Fi  
;XSV}eLu  
//线程睡眠 }ARWR.7Cc  
public static void sleep(int nSecond) #n]js7  
{ uNxR#S  
try{ xV}E3Yj2#  
Thread.sleep(nSecond); !3v!BJ#+,&  
} }?$d~]t)  
catch(Exception e) epJVs0W  
{ K;,n?Q w  
e.printStackTrace (); +IK~a9t  
} 8GN0487H  
} gnlGL[r|  
A/lxXy}D  
//日志 *^ \xH,.  
public static void log(String sMsg) F +D2 xN@  
{ 1mwb&j24n3  
System.err.println(sMsg); @E{c P%fv  
} ea3AcT6  
H\W60|z9  
ow:c$Zq  
public static void log(int sMsg) 15 x~[?!  
{ p )etl5  
System.err.println(sMsg); `][~0\Y3m  
} 6vQAeuz<Fq  
} KVvIo1$N  
 MScjq  
D@rOX(m  
/* eY"y[  
**TestMethod.java `E8m> q Ss  
*/ eVjr/nm  
package NetFox; 6{8qATLR  
q*{i/=~  
)Uw QsP  
public class TestMethod { :[#HP66[O5  
z `T<g!Y  
dz5a! e [  
public TestMethod() "S(m1L?  
{ ///xx/weblogic60b2_win.exe &"BmCDOq  
try{ ?=dyU(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Y\Vh}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k`62&"T  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;gc Q9L  
fileFetch.start(); ib/B!?/  
} MlkTrKdGi  
catch(Exception e){e.printStackTrace ();} AA;\7;k{  
eG72=l)Mz  
"pa5+N&2-  
} 6k%N\!_TUW  
F[ N{7C3  
W @Y$!V<  
public static void main(String[] args) \S[:  
{ , b ,`;I  
new TestMethod(); 1`Cr1pH  
} Q!7Er  
} "G)-:!H  
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