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http断点续传简单实现(java)

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/* gi\UNT9x  
**SiteFileFetch.java `&/zOMp  
*/ ~x +24/qT  
package NetFox; @j4~`~8  
import java.io.*; _~ 7cn  
import java.net.*; s8kkf5bu  
HR k^KB  
+)d7SWO6]!  
public class SiteFileFetch extends Thread { ]p~,C*UH0  
\3z^/F~  
|fm"{$u  
SiteInfoBean siteInfoBean = null; //文件信息Bean W;wu2'  
long[] nStartPos; //开始位置 ((_v>{  
long[] nEndPos; //结束位置 ;0++):30V  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #1f8A5<  
long nFileLength; //文件长度 *W<g%j-a  
boolean bFirst = true; //是否第一次取文件 u:4?$%rB  
boolean bStop = false; //停止标志 D'Sdz\:4  
File tmpFile; //文件下载的临时信息 JSiLG0  
DataOutputStream output; //输出到文件的输出流 P}Ule|&LK  
1hgmlY`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) B bx.RL.V  
public SiteFileFetch(SiteInfoBean bean) throws IOException *,__\/U98  
{ !7[Rhk7bW  
siteInfoBean = bean; +xtR`Y"  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <?iwi[S  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); y3C$%yv0  
if(tmpFile.exists ()) #9Dixsl*Q  
{ w-MnJ(r  
bFirst = false; Ndx  ]5  
read_nPos(); Nb;Yti@Y.  
} +Gvf5+ 5VR  
else Lv ,Ls  
{ <)(STo  
nStartPos = new long[bean.getNSplitter()]; )zVD!eG_9  
nEndPos = new long[bean.getNSplitter()]; ojd/%@+u+Y  
} # S4{,  
iPJZ%  
L$FLQyDR  
cB7=4:U  
} Iih~rWJ  
&wZ:$lK#o  
 0$l D  
public void run() E8Wgm 8  
{ s&$Zgf6Z  
//获得文件长度 Mzxy'U V  
//分割文件 5fBW#6N/  
//实例FileSplitterFetch -pR1xsG  
//启动FileSplitterFetch线程 x3my8'h@  
//等待子线程返回 +x0-hRD  
try{ Y&5h_3K;<  
if(bFirst) BY$%gIB6>  
{ CxtH?9# |  
nFileLength = getFileSize(); '%R Yo#  
if(nFileLength == -1) _, ;c2  
{ vf(\?Js ,  
System.err.println("File Length is not known!"); L +s,,k  
} {E`f(9r:  
else if(nFileLength == -2) . \fzK  
{ DY{JA *N  
System.err.println("File is not access!"); G?d28p',.  
} B;':Eaa@  
else ZuF-$]oL&  
{ X(#G6KeZFZ  
for(int i=0;i<nStartPos.length;i++) W%.Kr-[?`o  
{ ' 7>V4\"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); mY3x (#I  
} C;;dCsiV5  
for(int i=0;i<nEndPos.length-1;i++) avk0pY(n  
{  $3%EKi  
nEndPos = nStartPos[i+1]; 6 9,;=  
} t1.5hsp  
nEndPos[nEndPos.length-1] = nFileLength; A=|&N%lP'  
} e ?H`p"l  
} V4Ql6vg_f  
y:Qo:Z~  
Vo"\nj  
//启动子线程 #f~#38_  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :NO'[iE  
for(int i=0;i<nStartPos.length;i++) ;e_n7>'#%  
{ h5ST`jZ  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BxO8oKe  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hHdH#-O:4"  
nStartPos,nEndPos,i); 'zZN]P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #tdI;x3  
fileSplitterFetch.start(); Jpws1~  
} H{`S/>)[   
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <`a!%_LC [  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); grnlJ=  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z@ * ^4Ve  
nEndPos = " + nFileLength); a%sr*`  
// fileSplitterFetch[nPos.length-1].start(); W)?B{\  
aDTNr/I  
/WB^h6qg  
//等待子线程结束 \:\rkc9LI  
//int count = 0; O[;>Y'zqC%  
//是否结束while循环 < ppg$;  
boolean breakWhile = false; u:3~Ius  
=zt@*o{F  
kl_JJX6jPP  
while(!bStop) Edc<  8-  
{ ;+`t[ go  
write_nPos(); Y dmYE $  
Utility.sleep(500); ub6=^`>h  
breakWhile = true; @]t}bF]  
4WZ:zr N  
4}Y2 B$  
for(int i=0;i<nStartPos.length;i++) -S OP8G  
{ xf?*fm?m  
if(!fileSplitterFetch.bDownOver) sME3s-  
{ nWfOiw-t  
breakWhile = false; I8)x 0)Lx  
break; (qnzz!s  
} 3@*J=LGhKc  
} lphQZ{8  
if(breakWhile) r:2G11[  
break; +HQX]t:Y  
(2Z-NVU#  
9H$#c_zrq  
//count++; ds,NNN<HW  
//if(count>4) (\>3FwFHW|  
// siteStop(); +;tXk  
} hMh8)S  
iF?4G^  
%Iw6oG  
System.err.println("文件下载结束!"); _$]3&P  
} (PE x<r1   
catch(Exception e){e.printStackTrace ();} 9o"k 7$  
} V<Q''%k  
+1~Y2   
0qqk:h  
//获得文件长度 k*d0ws#<l  
public long getFileSize() Q\z6/1:9Z  
{ /qa{*"2Qo  
int nFileLength = -1; Tz[ck 'k  
try{ \3LP@;Phn  
URL url = new URL(siteInfoBean.getSSiteURL()); {b6| wQ\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z^j7wMQ  
httpConnection.setRequestProperty("User-Agent","NetFox"); kHygif !I4  
)-%3;e<w  
I !=ew |  
int responseCode=httpConnection.getResponseCode(); kAA1+rG  
if(responseCode>=400) =VFi}C/  
{ 'hN_H}U  
processErrorCode(responseCode); :rd{y`59>&  
return -2; //-2 represent access is error T^> ST  
} Zvz Zs  
kVR_?ch{  
Ybo:2e  
String sHeader; hkB/ OJ  
v1h\ 6r'  
)voJq\Y)%  
for(int i=1;;i++) Is1P,`*!  
{ <ZO"0oz%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /.P9n9  
//Utility.log(in.readLine()); `Y>'*4a\  
sHeader=httpConnection.getHeaderFieldKey(i); Z0HfrK#oU  
if(sHeader!=null) blO(Th&  
{ @yp#k>  
if(sHeader.equals("Content-Length")) 3m%oXT  
{ n@|5PI"bx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0z&]imU  
break; 3,`I\>No  
} O*0%AjT6  
} 6 G.(o  
else 'EzKu~*  
break; s^f7w  
} }C-K0ba7  
} E2dl}S zp  
catch(IOException e){e.printStackTrace ();} NULew]:5  
catch(Exception e){e.printStackTrace ();} jN))|eD0x  
[g )HoR=&  
%8Eu{3  
Utility.log(nFileLength); #gW"k;7P  
XhEZTg;  
B&:9uPRzZ  
return nFileLength; 6Qtyv  
} O2xbHn4  
` 1Ui  
Sc b'  
//保存下载信息(文件指针位置) u@&e{w~0  
private void write_nPos() ;wGoEN  
{ 0'wchy>  
try{ mIW8K ):  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |"]#jx*8KC  
output.writeInt(nStartPos.length); F8xz^UQO  
for(int i=0;i<nStartPos.length;i++) Hk&op P9)  
{ n_~u!Ky_P  
// output.writeLong(nPos); -gn!8G1  
output.writeLong(fileSplitterFetch.nStartPos); 74_':,u;]~  
output.writeLong(fileSplitterFetch.nEndPos); qa-%j+  
} jk (tw-B  
output.close(); |P_voht  
} >]{{5oOQ>  
catch(IOException e){e.printStackTrace ();} \/XU v(  
catch(Exception e){e.printStackTrace ();} ":v^Y 9  
} B*Z}=$1j  
^8.s"4{  
pyUzHF0  
//读取保存的下载信息(文件指针位置) &/m0N\n?  
private void read_nPos() ^%5 ;Sc1V  
{ pTB1I3=.u  
try{ m@Hg:DY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g)!d03Qoy  
int nCount = input.readInt(); c1tM(]&  
nStartPos = new long[nCount]; i[Qq,MmC  
nEndPos = new long[nCount]; [_T6  
for(int i=0;i<nStartPos.length;i++) &s#OiF8  
{ dzk1!yy  
nStartPos = input.readLong(); h ?_@nQ!  
nEndPos = input.readLong(); QXI#gA  =  
} ,_K y'B  
input.close(); w`GjQIA  
} :(Ak:  
catch(IOException e){e.printStackTrace ();} LbkQuq/d  
catch(Exception e){e.printStackTrace ();} n  +v(t  
}  h3 e %(a  
`\beQ(g  
F4NM q&_  
private void processErrorCode(int nErrorCode) fJ  GwT  
{ /&N\#;kK?b  
System.err.println("Error Code : " + nErrorCode); Ddh  
} I*z|_}$  
,UYe OM2Ao  
f4O}WU}l{s  
//停止文件下载 5{gv \S1  
public void siteStop() 7aS%;EU  
{ <<DPer2  
bStop = true; BN&eU'Dl]  
for(int i=0;i<nStartPos.length;i++) `*o ko[\3  
fileSplitterFetch.splitterStop(); =qvn?I^/  
FwE<_hq//  
U:AB%gr[  
} 5d;(D i5z  
} WN $KS"b6}  
//负责部分文件的抓取 Z*R~dHr   
**FileSplitterFetch.java /2Z7  
*/ W K(GR\@  
package NetFox; !q~f;&rg  
c8N pk<  
:IO"' b  
import java.io.*; ~tLvD[n[  
import java.net.*; "r=p/"4D  
$a|>>?8  
]k$:sX  
public class FileSplitterFetch extends Thread { ,V9 r2QY  
IL,iu  
dy~M5,zn  
String sURL; //File URL !gL1  
long nStartPos; //File Snippet Start Position CHi t{ @9  
long nEndPos; //File Snippet End Position 4Wu(Tps  
int nThreadID; //Thread's ID usNq]  
boolean bDownOver = false; //Downing is over 8M0<:p/  
boolean bStop = false; //Stop identical _}gfec4o  
FileAccessI fileAccessI = null; //File Access interface .NJ Ne  
]5Q)mWF  
4av  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Z0.H3  
{ "!Nu A  
this.sURL = sURL; J vl-=~  
this.nStartPos = nStart; {z9,CwJan?  
this.nEndPos = nEnd; ?Ld:HE  
nThreadID = id; P_P~c~o  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =Qn8Y`U  
} sY[!=`@  
rM4Ri}bS  
xouBBb=  
public void run() i)/#u+Y1P  
{ ;Za^).=  
while(nStartPos < nEndPos && !bStop) L*P*^I^1  
{ <'j ygZ(  
uG+eF  
_ t.E_K  
try{  wH\ K'/  
URL url = new URL(sURL); ?es9j]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ('`mPD,  
httpConnection.setRequestProperty("User-Agent","NetFox"); -^*8D(j*  
String sProperty = "bytes="+nStartPos+"-"; p`S~UBcL.  
httpConnection.setRequestProperty("RANGE",sProperty); Gx|/ Jq  
Utility.log(sProperty); 29W`L2L  
-j^G4J  
@7sHFwtar?  
InputStream input = httpConnection.getInputStream(); ,!^g8zO  
//logResponseHead(httpConnection); 6J965eM'[  
8SBa w'a  
PKev)M;C+  
byte[] b = new byte[1024]; SbobXTbG  
int nRead; CX7eCo  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5r0Sl89J  
{ rm<`H(cT  
nStartPos += fileAccessI.write(b,0,nRead);  ?QcS$i  
//if(nThreadID == 1) S,s") )A1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .4!wp&  
} orEb+  
wh3Wuh?x  
^J@ Xsl  
Utility.log("Thread " + nThreadID + " is over!"); ']sIU;h3  
bDownOver = true; -}5dZ;  
//nPos = fileAccessI.write (b,0,nRead); 08$l=  
} rY"EW"y  
catch(Exception e){e.printStackTrace ();} /b{Ufo3v  
} I^O`#SA(  
} j[w5#]&%  
Iy2AJ|d.  
S3dcE"hg  
//打印回应的头信息 OQ<NB7'n0A  
public void logResponseHead(HttpURLConnection con) LfsOGC  
{ CasFj9,  
for(int i=1;;i++) 8yGo\\=T  
{ "; ?^gA  
String header=con.getHeaderFieldKey(i); Bn Nu/02.=  
if(header!=null) mTa^At"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Csm23QLsg)  
Utility.log(header+" : "+con.getHeaderField(header)); wHErF #xo  
else ZQ~EaI9R  
break; k= 9a/M u  
} l 4cTN @E  
} (XQl2C  
-vS7%Fbr  
.:;#[Z{-  
public void splitterStop() 3 J\&t4q  
{ h='@Q_1Sb  
bStop = true; KkZo|\V  
} %[m%QP1;p  
BeM|1pe.  
":^cb =  
} ;7yt,b5&C  
V[">SiOg  
3q1u9`4;  
/* ptpu u=3"  
**FileAccess.java oz?6$oE(bt  
*//文件访问(定位,写) {q BbzBG  
package NetFox; btB> -pT  
import java.io.*; S]DYEL$  
_+nlm5  
v:Z.8m8D  
public class FileAccessI implements Serializable{ ]m""ga  
0bG2YMs  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f@J-6uQ7w  
RandomAccessFile oSavedFile; J_ `\}55n  
long nPos; O0> ^?dsL  
%D*yXNsY  
%-[U;pJe;  
public FileAccessI() throws IOException w77"?kJ9X  
{ C AF{7 `{  
this("",0); 3.I:`>;EO  
} zI3Bb?4.  
qn@:A2e d  
.cm$*>LW:x  
public FileAccessI(String sName,long nPos) throws IOException Uzd\#edxJ  
{ =Qw`F0t  
oSavedFile = new RandomAccessFile(sName,"rw"); 6\?< :Qto  
this.nPos = nPos; ,(CIcDJ2U_  
oSavedFile.seek(nPos); fmq9u(!R  
} _cH 7lO[  
8Dy;'BtT  
~@bh[o~rF  
public synchronized int write(byte[] b,int nStart,int nLen) <f`G@  
{ 421ol  
int n = -1; |0/~7l  
try{ khtSZ"8X  
oSavedFile.write(b,nStart,nLen); fP:g}Z  
n = nLen; 6'qC *r   
} [!#<nY/C  
catch(IOException e) :*/`"M)'  
{ V3$Yr"rZ;  
e.printStackTrace (); Q{+&3KXH  
} -:o4|&g<*  
<; Bv6.Z  
X,8 ]g.<  
return n; %2D9]L2Up  
} m dTCe HX  
/a!M6:,pX  
~1v5H]T{  
} 6S# e?>"+  
\P|PAU@,  
&I$MV5)u  
/* %Cz&7qf"  
**SiteInfoBean.java 7U\GX  
*/ $kef_*BQg  
package NetFox; N8^ AH8l  
{"uLV{d  
:v!e8kM\x  
public class SiteInfoBean { .v{ok,&  
{FU,om9  
u 6(O;  
private String sSiteURL; //Site's URL +bw>9VmG  
private String sFilePath; //Saved File's Path Bqd'2HQd  
private String sFileName; //Saved File's Name af<R.  
private int nSplitter; //Count of Splited Downloading File MIJ^ n(-G  
'-7rHx  
cn$o$:tW  
public SiteInfoBean() =k\V~8XZ  
{//nSplitter的缺省值为5 sV)) Z2sq  
//default value of nSplitter is 5 kgV_*0^  
this("","","",5); $R2iSu{kO  
} B~RVFc +  
7xIXFuu  
ROyG+dUy  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +I {ZW}rA  
{ %9!, PeRe  
sSiteURL= sURL; vO#=]J8`  
sFilePath = sPath; qQu}4Ye>  
sFileName = sName; .MzVc42<  
this.nSplitter = nSpiltter; '*~_!lE5  
+ S^OzCGk  
AUm"^-@x#>  
} 4iD-jM_D  
q`l%NE  
8tR(i[L   
public String getSSiteURL() 1yS [;  
{ o& GS;{Rs  
return sSiteURL; ur,!-t(~t  
} vjcG F'-  
O"$uw  
LK}Ih@ f  
public void setSSiteURL(String value) IezOal  
{ PtUea  
sSiteURL = value; WPmH4L>T  
} 0Y_?r$M  
wE.CZ% f  
Vy:I[@6@+  
public String getSFilePath() ' DZYN {}  
{ \{HbL,s  
return sFilePath; (}W+W\.  
} E,S[3+  
OO Hw-MW  
x +=zG4Hm  
public void setSFilePath(String value) "%o,P/<X  
{ H\Y5Fd9)  
sFilePath = value; 7hs1S|  
} lTe7n'y^^  
8!~8:?6n  
OT*C7=  
public String getSFileName() Ho}"8YEXNV  
{ ''{REFjK7  
return sFileName; -VqZw&"  
} kK27hfsw  
$)1i)/]9U  
yJCqP=  
public void setSFileName(String value) 66P'87G  
{ WF)(Q~op0U  
sFileName = value; 0Jz5i4B  
} n9 LTrhLqp  
3@qy}Nm  
0zQ^ 6@  
public int getNSplitter() @H{QHi  
{ O_zW/#  
return nSplitter; 9{D u)k  
} i++a^f  
+VJS/  
`&\jOve   
public void setNSplitter(int nCount) n(i Uc1Y  
{ ;_o1{?~  
nSplitter = nCount; y$ L@!r/s  
} g[oa'.*OB  
} +3a} ~pW  
9j0Hvo%T  
m* Zq3j  
/* $+ z 3  
**Utility.java W'|NYw_B  
*/ J`E,Xw>2  
package NetFox; 1JRM@!x  
#%4XZ3j#j;  
YUzx,Y>k  
public class Utility { jGg,)~)Y  
y:Wq;xEiDo  
7Ei,L[{\i#  
public Utility() wbIgZ]o!/;  
{ @q98ac*{  
s+tPHftp  
I_1(jaY  
} (yx^zW7  
_Sq*m=  
//线程睡眠 9HsiAi*  
public static void sleep(int nSecond) X#ZQpo'h  
{ .wU0F  
try{ j*.K|77WHj  
Thread.sleep(nSecond); YiO3.+H  
} 6'{/Ote  
catch(Exception e) _>8rTk`/h  
{ ,Y:ET1:  
e.printStackTrace (); `D%U5Jb  
} Wc*jTip  
} &RJ*DAmL  
^n?`l ^9c$  
//日志 / 5!0wxN  
public static void log(String sMsg) V< Ib#rd'  
{ 5*O*p `Ba  
System.err.println(sMsg); J~]Y  
} ~WjK'N4n5  
HUA{ P%  
"t.Jv%0=  
public static void log(int sMsg) 0P 5s'2w  
{ ]c9\[Kdq}H  
System.err.println(sMsg); yTxrbE  
} C`@gsF"<7  
} CN{xh=2qY[  
(# c|San  
tD~ n PbbB  
/* e=cb%  
**TestMethod.java u|mTF>L  
*/ r4isn^g  
package NetFox; }@y(-7t  
/E39Z*  
:`>$B?x+  
public class TestMethod { 4St-Q]Y _  
lR>p  
+a'LdEp  
public TestMethod() /szwVA  
{ ///xx/weblogic60b2_win.exe ELN1F0TneH  
try{ ;e"dxAUe!^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Op'&c0l  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '8yCwk  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'ti~TG  
fileFetch.start(); bess b>=  
} Hl#?#A5  
catch(Exception e){e.printStackTrace ();} +8|9&v`  
E !9(6G4  
EzeU-!|W  
} n *EGOS  
^OOoo2  
lu?:1V-  
public static void main(String[] args) ]$,3vYBf  
{ #`ZBA>FLaQ  
new TestMethod(); b8 E{~z  
} a&Z,~Vp  
} G=F_{z\}  
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