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http断点续传简单实现(java)

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/* hv  
**SiteFileFetch.java <4LW.q  
*/ F?z:[1(:  
package NetFox; vfd<qdi3p(  
import java.io.*; /0swrt.  
import java.net.*; ,i jB3J  
}qw->+nD  
 Vp7d  
public class SiteFileFetch extends Thread { MY60%  
C'y4 ~7  
`fuQ t4  
SiteInfoBean siteInfoBean = null; //文件信息Bean nt]'>eX_}  
long[] nStartPos; //开始位置 DPlDuUOd  
long[] nEndPos; //结束位置 {Gr"lOi*@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 hgj ]Jr  
long nFileLength; //文件长度 _1?nLx7n  
boolean bFirst = true; //是否第一次取文件 XDYQV.Bv  
boolean bStop = false; //停止标志 5tI#UBha  
File tmpFile; //文件下载的临时信息 zfD@/kU  
DataOutputStream output; //输出到文件的输出流 &cWC&Ws"  
{wDq*va  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) +/[L-&,  
public SiteFileFetch(SiteInfoBean bean) throws IOException  bUsX~R-  
{ *rgF[ :  
siteInfoBean = bean; ?f$U8A4lp  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -Qn l)JB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )Q 5 x%  
if(tmpFile.exists ()) dWx@<(`OC  
{ VA>0Y  
bFirst = false; HUAbq }  
read_nPos(); 3(Ns1/;?,  
} '3w%K+eJY  
else YV8PybThc  
{ #bJp)&LO  
nStartPos = new long[bean.getNSplitter()]; \@Gcx}Y8h  
nEndPos = new long[bean.getNSplitter()]; ~,_@|,)  
} !|W.YbS  
eslvg#Q  
]v/pMg#-  
r$1b=m,0d  
} ,#czx3?4  
=r)LG,w212  
G|*&owJ  
public void run() 67;6nXG0K  
{ Ma'#5)D  
//获得文件长度 m*L5xxc!  
//分割文件 [8<0Q_?,  
//实例FileSplitterFetch Qgf\"s  
//启动FileSplitterFetch线程 '6kD6o_p1  
//等待子线程返回 Rt5,/Q0  
try{ cij8'( "+!  
if(bFirst) oiIl\#C  
{ Kx?.g#>U;  
nFileLength = getFileSize(); ]%ewxF  
if(nFileLength == -1) 9[`c"Pd  
{ ]WzeJ"r {3  
System.err.println("File Length is not known!"); ^9`|QF  
} joDqv,iW8  
else if(nFileLength == -2) +!GJ  
{ gKY6S?  
System.err.println("File is not access!"); }$'XV.  
} GKbbwT0T|  
else H+562W  
{ #sg*GK+|:R  
for(int i=0;i<nStartPos.length;i++) +J85Re `  
{ kS35X)-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ^D]J68)#a  
} blWtC/!Aq;  
for(int i=0;i<nEndPos.length-1;i++) H|0-Al.{  
{ eIEL';N6  
nEndPos = nStartPos[i+1]; W':b6}?  
} @U4hq7xzV2  
nEndPos[nEndPos.length-1] = nFileLength; l[]cUE  
} ) "?eug}D  
} d&+0JI<  
?K;l 5$?%  
jU kxA7 }}  
//启动子线程 Yg?BcY\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tUuARo7#  
for(int i=0;i<nStartPos.length;i++) Y]*&\Ex"\  
{ %Oo f/q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \4LTViY]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Fg 8lX9L  
nStartPos,nEndPos,i); (c&%1bJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IBvn q8\  
fileSplitterFetch.start(); S8B?uU  
} ZqdoYU'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nbB*d@"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,  O/IY  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", : 5['V#(o  
nEndPos = " + nFileLength); Ozhn`9L+1!  
// fileSplitterFetch[nPos.length-1].start(); 6" <(M@  
xmEom  
Y+o\?|q-E  
//等待子线程结束 [KFCc_:  
//int count = 0; q2r$j\L%  
//是否结束while循环 $.t>* Bq  
boolean breakWhile = false; mBJr*_p  
D)pTE?@W'  
).IyjHY  
while(!bStop) vBJxhK-  
{ 8MI8~  
write_nPos(); uO-|?{29  
Utility.sleep(500); c_CVZR?  
breakWhile = true; g~b$WV%  
Bu&9J(J1  
_si5z  
for(int i=0;i<nStartPos.length;i++) @tPr\F  
{ K3<A<&W_-  
if(!fileSplitterFetch.bDownOver) ;BqCjS%`N  
{ n((A:b  
breakWhile = false; zfE8=d8U  
break; >MKj~Ud  
} k0O5c[ j  
} %LzARTX  
if(breakWhile) _yUYEq<`  
break; S6_:\Q  
*Ti"8^`6  
]j>`BK>FE  
//count++; XXhN; -p  
//if(count>4) W8$0y2  
// siteStop(); 122s 7A  
} JBLUX,  
<&3aP}  
~".@;Q  
System.err.println("文件下载结束!"); Zhv%mUj~  
} VH~YwO!x  
catch(Exception e){e.printStackTrace ();} :F@Uq<~(  
} 2IE\O 8b  
YvcV801Go  
x{8h3.ZQ,  
//获得文件长度 b>8TH-1t~  
public long getFileSize() A6 .wXv,  
{ JB].ht  
int nFileLength = -1; @{q<"hT  
try{ \o/eF&  
URL url = new URL(siteInfoBean.getSSiteURL()); M2w'cdHk  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#M>b:"t e  
httpConnection.setRequestProperty("User-Agent","NetFox"); Dw7Xy}I/  
\>pm (gF  
'2i !RT-  
int responseCode=httpConnection.getResponseCode(); ^9Cu?!xu0  
if(responseCode>=400) q^sZP\i,*;  
{ ,c  ^nW  
processErrorCode(responseCode); "OK[uug  
return -2; //-2 represent access is error 9M3"'^ {$  
} NN=^4Xpc:  
z'$1$~I  
G`kz 0Vk  
String sHeader; U|Gy9"  
__Ksn^I   
Hnk&2bY  
for(int i=1;;i++) aA52Li  
{ P_NF;v5 v  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~gW^9nWYU  
//Utility.log(in.readLine()); d)bsyZ;U  
sHeader=httpConnection.getHeaderFieldKey(i); :>;F4gGVG  
if(sHeader!=null) r~h#  
{ LtX53c  
if(sHeader.equals("Content-Length")) R'zi#FeP  
{ v\4<6Z:4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *9$SFe|&n:  
break; jq*`| m;Q  
} j}",+H v  
} pv sa?z;rP  
else 0"% dPKi  
break; ;aW k-  
} ;h+~xxu=X  
} [RN]?,  
catch(IOException e){e.printStackTrace ();} :o{,F7(P  
catch(Exception e){e.printStackTrace ();} Gj-nT N  
\>Rfa+  
|k90aQO  
Utility.log(nFileLength); -5 PVWL\  
rvy%8%e?  
^7gKs2M  
return nFileLength; 0V>Ho H   
} 5!fYTo|G>  
r>FwJm!  
]#^v754X^T  
//保存下载信息(文件指针位置) ]S[/ a  
private void write_nPos() E5)0YYjHZ  
{ 9l &q}  
try{ 6V]m0{:E  
output = new DataOutputStream(new FileOutputStream(tmpFile)); :,aY|2si  
output.writeInt(nStartPos.length); zA>X+JH>iw  
for(int i=0;i<nStartPos.length;i++) !|xB>d q?  
{ QJ4$) Fr(  
// output.writeLong(nPos); `3i>e<m~  
output.writeLong(fileSplitterFetch.nStartPos); <MkvlLu((o  
output.writeLong(fileSplitterFetch.nEndPos); ~Ay)kv;  
} @}g3\xLiK  
output.close(); }URdoTOvb  
} :R=6Ku>  
catch(IOException e){e.printStackTrace ();} -wiQ d@X  
catch(Exception e){e.printStackTrace ();} 4xmJQ>/  
} J|f29B-c  
c_*w<vJ-'  
i$<['DY  
//读取保存的下载信息(文件指针位置) 5X)M)"rq;V  
private void read_nPos() *$-X&.h[  
{  jb&MC 2  
try{ y< *-&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v { >3)$1  
int nCount = input.readInt(); JOY&YA$U  
nStartPos = new long[nCount];  XyE$0i~t  
nEndPos = new long[nCount]; ^ZQMRNP{r  
for(int i=0;i<nStartPos.length;i++) }rfikm  
{ "Mj#P9  
nStartPos = input.readLong(); m =b7 r  
nEndPos = input.readLong(); i83~&Q=  
} 8R3{YJ6@T  
input.close(); xt?-X%oY8  
} \Dq'~ d  
catch(IOException e){e.printStackTrace ();} rN} 8~j  
catch(Exception e){e.printStackTrace ();} bc'IoD/  
} 2wY|E<E  
EwN{|34C  
^_Hf}8H7]  
private void processErrorCode(int nErrorCode) f1ANziC;i  
{ GT<oYrjU  
System.err.println("Error Code : " + nErrorCode); d'ZNp2L  
} }`<&l  
Ph[MXb:*  
D/."0 #q  
//停止文件下载 /Rq\Mgb  
public void siteStop() "x=\mA#`  
{ '?veMX  
bStop = true; w/nohZF6H  
for(int i=0;i<nStartPos.length;i++) ~h3G}EH  
fileSplitterFetch.splitterStop(); ?<!q F:r:  
Uw.')ZY=  
Z5 IWoY  
} OA3J(4!"W  
} MZ,1mR  
//负责部分文件的抓取 <N=k&\  
**FileSplitterFetch.java YJ6~P   
*/ W34xrm  
package NetFox; BjvQ6M{Y"+  
2 3PRb<q  
-|m3=#  
import java.io.*; JK =A=  
import java.net.*; #!R>`l(S  
}b(h D|e  
Mc@9ivwL#  
public class FileSplitterFetch extends Thread { JfN5#+_i  
$3HqVqF^R  
 *XhlIQ  
String sURL; //File URL JKM(fX+  
long nStartPos; //File Snippet Start Position 0AQ4:KV(Y  
long nEndPos; //File Snippet End Position I </P_:4G  
int nThreadID; //Thread's ID f $Agcy  
boolean bDownOver = false; //Downing is over "i;.>  
boolean bStop = false; //Stop identical sq_>^z3T  
FileAccessI fileAccessI = null; //File Access interface c]|vg=W  
1PwtzH .w  
7 <^+)DsS?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R xITMt  
{ \yJ 4+vo2Q  
this.sURL = sURL; +QFKaS<sn  
this.nStartPos = nStart; !+PrgIp>  
this.nEndPos = nEnd; dRron_'  
nThreadID = id; Jj \ nye+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hUlRtt  
} _  Lh0  
_C/|<Ot:  
L K #A  
public void run() o7!A(Eu  
{ _k2R^/9Ct%  
while(nStartPos < nEndPos && !bStop) QAV6{QShj  
{ dP8qP_77A~  
kT@ITA22  
I+& T}R  
try{ A`3KE9ED  
URL url = new URL(sURL); '0+I'_(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  ydzsJ+dx  
httpConnection.setRequestProperty("User-Agent","NetFox"); d*^JO4'  
String sProperty = "bytes="+nStartPos+"-"; VxN#\D i&  
httpConnection.setRequestProperty("RANGE",sProperty); as:l1S   
Utility.log(sProperty); 5?>4I"ne  
KY  
l[T-Ak  
InputStream input = httpConnection.getInputStream(); )4ek!G]Rb  
//logResponseHead(httpConnection); F+H]{ss>  
v8f3B<kj  
@GKDSS4jv  
byte[] b = new byte[1024]; SiaNL:  
int nRead; Z?o0Q\ }1  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aze#Cn,P}  
{ ElW\;C:K*  
nStartPos += fileAccessI.write(b,0,nRead); MeBTc&S<  
//if(nThreadID == 1) Z2]0brV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mKe6rEUs|  
} S5hc@^|0Z  
arm_SyL0  
XS&Pc  
Utility.log("Thread " + nThreadID + " is over!"); *U1*/Q.  
bDownOver = true; ?_gvI  
//nPos = fileAccessI.write (b,0,nRead); nnPT08$  
} \XB,)XDB  
catch(Exception e){e.printStackTrace ();} swj\X ,{  
} m=6?%' H}  
} v)du]  
9Ad%~qciY  
1!1JT;gG^9  
//打印回应的头信息 4~Cf_`X}]  
public void logResponseHead(HttpURLConnection con) Jq` Dvz  
{ Gky*EY  
for(int i=1;;i++) m-O*t$6  
{  ,h^6y  
String header=con.getHeaderFieldKey(i); QIkFX.^  
if(header!=null) gV@xu)l  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aftt^h  
Utility.log(header+" : "+con.getHeaderField(header)); @sn:%/x_  
else "Y+VNS  
break; `?$-T5Rr  
} yT/rH- j;5  
} 7-B|B{]  
r B+ (  
epnZGz,A  
public void splitterStop() mHMsK}=~  
{ DIGw4g4Kt  
bStop = true; 6Mc&=}bV  
} k5\V:P=#  
t[!,puZc#  
M#^q <K %  
} D/=05E%[81  
Lmjd,t  
Gk5'|s  
/* ]#M"|iTR  
**FileAccess.java 2*D2jw  
*//文件访问(定位,写) F4\:9ws  
package NetFox; aZ~e;}w.Zq  
import java.io.*; rwDLBpk  
N#M>2b<A/T  
: _Y^o  
public class FileAccessI implements Serializable{ \xS X'/G  
h:pgN,W}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PNAvT$0LaZ  
RandomAccessFile oSavedFile; rmw}Ui"  
long nPos; 2Di~}*9&  
ByjfPb#  
]B(}^N>WH  
public FileAccessI() throws IOException l#cVQ_^"  
{ Kc]cJ`P4.  
this("",0); mdL T7  
} ? /!Fv/  
|E K6txRb  
RbUir185Y  
public FileAccessI(String sName,long nPos) throws IOException +DSbr5"VlB  
{ )q'dX+4=eL  
oSavedFile = new RandomAccessFile(sName,"rw"); w31O~Ve  
this.nPos = nPos; ^kNVQJiZyG  
oSavedFile.seek(nPos); =Jl\^u%H(x  
} [Uk cG9  
?5">50  
\_.'/<aQ  
public synchronized int write(byte[] b,int nStart,int nLen) mL1ZSX o!  
{ 1R-0b{w[  
int n = -1; 1W*Qc_5 v1  
try{ ?:vg`m!*  
oSavedFile.write(b,nStart,nLen); wOL%otEf  
n = nLen; 53uptQ{   
} 60~*$`  
catch(IOException e) MDa[bQ NM  
{ FsUH/Y y  
e.printStackTrace (); '*Y mYU  
} Nkb%4ofKqu  
9hK8dJw  
* g+v*q X  
return n; o7we'1(O  
} im<!JMI  
C|H`.|Q  
a.u{b&+9  
} ?z)2\D  
\Yp"D7:Qi  
t#M[w|5?  
/* ';.TQ_I7Y  
**SiteInfoBean.java o$bQ-_B`  
*/ Y]R=z*i%  
package NetFox; EO'+r[Y  
9J%O$sF  
Q +hOW-  
public class SiteInfoBean { br0\O  
+ ,]&&  
xz@*V>QT  
private String sSiteURL; //Site's URL ly!3~W  
private String sFilePath; //Saved File's Path *W2] Kxx*  
private String sFileName; //Saved File's Name Pi[]k]XA\  
private int nSplitter; //Count of Splited Downloading File q:vN3#=^qf  
hTAc}'^$  
$igMk'%Nmb  
public SiteInfoBean() ZK{1z|  
{//nSplitter的缺省值为5 w2 (}pz:  
//default value of nSplitter is 5 unYPvrd  
this("","","",5); oVuIHb0w  
} 5Mxl({oI]  
cJT_Qfxx  
S%]4['Y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4myikeUR_  
{ 5Q}HLjG8Z  
sSiteURL= sURL; !bK;/)  
sFilePath = sPath; #/(L.5d[  
sFileName = sName; :'t"kS  
this.nSplitter = nSpiltter; \py&v5J)s!  
N<(rP1)`v  
9%k4Ic%P  
} ! , ]Fx  
Qmd2C&Xw  
+CEt:KQ   
public String getSSiteURL() #I ,c'Vj  
{ %D7^.  
return sSiteURL; /ORK9 g  
} KPK`C0mg@k  
|<]wM(GxE  
%RIu'JXi  
public void setSSiteURL(String value) ctb , w  
{ pdQaVe7tRo  
sSiteURL = value; M(^IRI-  
} -uAGG?ZER  
dg N #"  
cw BiT  
public String getSFilePath() _ Axw$oYS  
{ qqYQ/4Ajw  
return sFilePath; dZ,7q_r,~  
} tr 8Q{  
N:^4On VR  
C`oB [  
public void setSFilePath(String value) }D~m%%,  
{ &@&^k$du8q  
sFilePath = value; ='/#G0W  
} Y% [H:  
&6Wim<*  
jN+2+P%OL  
public String getSFileName() mh_GYzd  
{ \bSakh71  
return sFileName; H/#WpRg  
} fK4O N'[R:  
)]}68}9  
Df $Yn  
public void setSFileName(String value) z_&T>ME  
{ x6yO2Yo  
sFileName = value; ,l)AYu!q4F  
} k"`^vV[{F  
Z!?T&:  
j~ qm5}  
public int getNSplitter() G#^6H]`[J:  
{ G|$n,X1O(  
return nSplitter; dfeN_0` -  
} B<!wh  
1N8YD .3  
BGT`) WP  
public void setNSplitter(int nCount) xiQd[[(sM  
{ 1$c[G}h  
nSplitter = nCount; kb*b|pWlO  
} =?B[oq  
} vinn|_s%  
na/,1iI<  
7 (i\?  
/* n22OPvp  
**Utility.java jAFJ?L(  
*/ 7mS_Cz+cB  
package NetFox; 0vz!)  
H%Sx*|  
Gc!&I+kd  
public class Utility { '^t(=02J  
2f0_Xw_V_  
|i'w"Tz4  
public Utility() Uv3Fe%>  
{ ~!dO2\X+  
(7P VfS>;  
E+aE5wmr  
} Luh*+l-nO  
y=WCR*N  
//线程睡眠 p["20 ?^  
public static void sleep(int nSecond) B\7 80p<  
{ t4,(W`  
try{ FE?^}VH  
Thread.sleep(nSecond); ^t)alNGos  
} O$& 4{h`  
catch(Exception e) k{C|{m  
{ )0@&pEObm  
e.printStackTrace (); ^$\#aTyFK  
} {[FJkP2l  
} 8F`799[p  
R 9Y k9v  
//日志 yCye3z.  
public static void log(String sMsg) ZltY_5l  
{ 2W`<P2IA  
System.err.println(sMsg); {&Sr<d5  
} 8J#TP7;  
H Ff9^  
LfS]m>>e  
public static void log(int sMsg) )pt#Pu  
{ N Y~y:*:Q  
System.err.println(sMsg); ehYGw2  
} []eZO_o6j  
} bMF`KRP2  
9RN! <`H  
qgLj^{  
/* ]a=Bc~g91  
**TestMethod.java !xZ`()D#  
*/ Ja6PX P]'  
package NetFox; qeZ*!H6-  
u'EzYJ7  
E@$HO_;&  
public class TestMethod { c`G~.paY|  
V4 Wn  
|zSoA=7?  
public TestMethod() %L;'C v  
{ ///xx/weblogic60b2_win.exe +LAjh)m  
try{ qw%wyj7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }>u<,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5U&?P   
SiteFileFetch fileFetch = new SiteFileFetch(bean); &8wluOs/5  
fileFetch.start(); 3sq(FsT  
} *6%r2l'kZ  
catch(Exception e){e.printStackTrace ();} '@+a]kCMev  
{VrjDj+Xy  
<swY o<?J#  
} vErlh:~e  
#EdsB  
['n;e:*  
public static void main(String[] args) $3MYr5  
{ HGRH9W  
new TestMethod(); 6*H F`@(  
} 'xY@ I`x  
} s\dF7/b  
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