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http断点续传简单实现(java)

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/* EmT`YNuc  
**SiteFileFetch.java h<\_XJJ  
*/ H<G4O02i_  
package NetFox; 3TZ*RPmFRm  
import java.io.*; kY&h~Q  
import java.net.*; =@5x"MOz  
v^7LctcVm  
EK$Kee}~  
public class SiteFileFetch extends Thread { vHE^"l5v  
K!mOr  
&h,5:u  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,*@AX>  
long[] nStartPos; //开始位置 on7I l  
long[] nEndPos; //结束位置 oq_6L\ ~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 EIf ~dOgH  
long nFileLength; //文件长度 Q!FLR>8  
boolean bFirst = true; //是否第一次取文件 #s%-INcR  
boolean bStop = false; //停止标志 ?<yM7O,4  
File tmpFile; //文件下载的临时信息 @&hnL9D8lL  
DataOutputStream output; //输出到文件的输出流 45H!;Q sk  
)*d W=r/$V  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) sfVf@0g  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5]1h8PW!Y  
{ pBC<u  
siteInfoBean = bean; {A o,t+j  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .\qj;20W  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 90Hjx>[  
if(tmpFile.exists ()) 2w$t wW-  
{ V8~jf-\$b  
bFirst = false; 6R29$D|HFO  
read_nPos(); *AIEl"29  
} 9=/N|m8.  
else Bz`yfl2  
{ )P>u9=?,=E  
nStartPos = new long[bean.getNSplitter()]; D8# on!  
nEndPos = new long[bean.getNSplitter()]; 5b6s4ZyV  
} ,s^<X85gp\  
6dEyv99  
-)y%~Zn  
ib0g3p-Lc  
} 'iLH `WE  
{hO`6mr&t  
H2-28XGc  
public void run() @l UlY2  
{ te4= S  
//获得文件长度 VRW] a  
//分割文件 ehAu^^Q>  
//实例FileSplitterFetch HZ*0QgW\(5  
//启动FileSplitterFetch线程 I6LD)?  
//等待子线程返回 SgE/!+{  
try{ =BZ?-mIU  
if(bFirst) XO F1c3'H  
{ #m8sK(#lo  
nFileLength = getFileSize(); EC?Efc+O  
if(nFileLength == -1) 5H:@ 8,B  
{ Kt.~aaG_  
System.err.println("File Length is not known!"); ;#G%U!p  
} sxED7,A  
else if(nFileLength == -2) 0D(cXzQP  
{ i$-#dc2qY  
System.err.println("File is not access!"); sst,dA V$  
} Cv=GZGn-  
else b]]N{: I  
{ ^Dx#7bsDZR  
for(int i=0;i<nStartPos.length;i++) ]wuy_+$  
{ +TRy:e  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); cUDgM  
} !@ YXZ  
for(int i=0;i<nEndPos.length-1;i++) WO,xMfK  
{ [ev-^[  
nEndPos = nStartPos[i+1]; u>Ki$xP1  
} ZZ)G5ji  
nEndPos[nEndPos.length-1] = nFileLength; swpnuuC-  
} "L2m-e6  
} :a< hQ|p  
} IlP:  
g3?U#7i  
//启动子线程 hQgN9S5P  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S9Yt1qb  
for(int i=0;i<nStartPos.length;i++) 3#<* k>1G?  
{ %>XN%t'6aT  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | D.C!/69  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P?3{z="LzJ  
nStartPos,nEndPos,i); 77 :'I  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wh~s Z  
fileSplitterFetch.start(); uf@U:V  
} O=jN&<rb  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DPJh5d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MPRO !45Z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3^G96]E  
nEndPos = " + nFileLength); mT_GrIl[  
// fileSplitterFetch[nPos.length-1].start(); g<[rH%\6fg  
dA#{Cn;  
F1A1@{8bN  
//等待子线程结束 v29G:YQe  
//int count = 0; "~p+0Xws9  
//是否结束while循环 G+Dpma ]  
boolean breakWhile = false; ZcZ;$*  
j.QHkI1.  
z*.v_Mx  
while(!bStop) -WT3)On  
{ e!o(g&wBj  
write_nPos(); TvrwVL)  
Utility.sleep(500); Gidkt;lj  
breakWhile = true; ~|) 9RUXr>  
4S *,\q]q  
!z=pP$81  
for(int i=0;i<nStartPos.length;i++) d]M[C[TOX  
{ 2X @G"  
if(!fileSplitterFetch.bDownOver) } 21j  
{ .u< U:*  
breakWhile = false; '>^Xqn  
break; ( D}" &2  
} |@`"F5@,  
} *:arva5  
if(breakWhile) 6f}e+80  
break; 3%M.U)|+  
E8tD)=1  
+?e}<#vd'?  
//count++; 4 10:%WGc  
//if(count>4) OKQLv+q5K)  
// siteStop(); 5V|tXsy:  
} POBpJg  
_ +KmNfR  
glor+  
System.err.println("文件下载结束!"); B/Ba5z"r$  
} #S i|!  
catch(Exception e){e.printStackTrace ();} 3Hm7 uBZ  
} q 22/_nSC  
%}F"*.  
zPQ$\$7xB  
//获得文件长度 W#45a.v  
public long getFileSize()  6`"ZsO  
{ j<$R4A 1  
int nFileLength = -1; f8!l7{2%q  
try{ sfC@*Y2XT  
URL url = new URL(siteInfoBean.getSSiteURL()); +{xG<Wkltz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FT_k^CC  
httpConnection.setRequestProperty("User-Agent","NetFox"); b]dxlj} <  
s, -*q}  
|+/$ g.  
int responseCode=httpConnection.getResponseCode(); eG^z*`**  
if(responseCode>=400) 0Uaem  
{ $SF3odpt  
processErrorCode(responseCode); Th+|*=Il  
return -2; //-2 represent access is error hgj0tIi/  
} s=\7)n=,M  
em/Xu  
mCrU//G  
String sHeader; {Pvr??"r  
Isp_U5M  
3YRB I|XO  
for(int i=1;;i++) ;@'0T4Z&l  
{ P6E1^$e  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); au A.6DQ  
//Utility.log(in.readLine()); n +d J c  
sHeader=httpConnection.getHeaderFieldKey(i); *cy.*@d  
if(sHeader!=null) 2?H@$-x>  
{ ,^!Zm^4,  
if(sHeader.equals("Content-Length")) GFY-IC+fc  
{ Deog4Ol"/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K*[0dza$  
break; "DzG Bu\  
} *e,CDV  
} intvlki]be  
else S r[IoF)  
break; m^c%]5$  
} @6[x%j/!bt  
} %8g$T6E[<2  
catch(IOException e){e.printStackTrace ();} TwwIt5_fN  
catch(Exception e){e.printStackTrace ();} ,iohfZz  
w=gQ3j#s  
{z-NlH  
Utility.log(nFileLength); yvS^2+jW  
+%x^RV}  
ZG!x$ yi$  
return nFileLength; R$ v i!0  
} _=)!xnYf  
;,FT&|3o  
O<Jwaap  
//保存下载信息(文件指针位置) i$g|?g~]  
private void write_nPos() Mf#2.TR  
{ a'm!M:w  
try{ Age-AJ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); - =yTAx  
output.writeInt(nStartPos.length); wiKCr/  
for(int i=0;i<nStartPos.length;i++) .M}06,-  
{ ]zX\8eHp!  
// output.writeLong(nPos); D@2Ya/c  
output.writeLong(fileSplitterFetch.nStartPos); ^CO#QnB @  
output.writeLong(fileSplitterFetch.nEndPos); kaV%0Of]  
} }t}38%1i  
output.close(); M2a}x+5'  
} dzpj9[  
catch(IOException e){e.printStackTrace ();} ~igRg~k:/  
catch(Exception e){e.printStackTrace ();} _J +]SNk  
} il=?of\,i  
'/n\Tg+  
Xk 5oybDI  
//读取保存的下载信息(文件指针位置) @_G` Ok4  
private void read_nPos() rK*hTjVn  
{ m]E o(P4+  
try{ , &-S?|  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BllDWKb  
int nCount = input.readInt(); <r@bNx@T  
nStartPos = new long[nCount]; mMn2(  
nEndPos = new long[nCount]; I4A ;  
for(int i=0;i<nStartPos.length;i++) Cl%V^xTb  
{ cF-Jc}h  
nStartPos = input.readLong(); tbL1g{Dz,  
nEndPos = input.readLong(); R %Rv  
} BYTXAZLb  
input.close(); S6= \r{V  
} =mDy@%yx!  
catch(IOException e){e.printStackTrace ();} %{7$ \|;J'  
catch(Exception e){e.printStackTrace ();} Qf/j:  
} tzx:*  
Rs`Vr_?Hk  
+>n. T  
private void processErrorCode(int nErrorCode) k*A4;Bm  
{ k?!TjBKm  
System.err.println("Error Code : " + nErrorCode); kO /~i  
} H0 {Mlu9  
aY3pvOV  
s{b0#[  
//停止文件下载 O8!!UA8V  
public void siteStop() l#mqV@?A~  
{ JDIz28Ww  
bStop = true; VGq{y{(  
for(int i=0;i<nStartPos.length;i++) zS&7[:IRs'  
fileSplitterFetch.splitterStop(); =>E44v  
2 rbX8Y  
[YL sEo=  
} WBIQ%XB'  
} (, ;MC/l  
//负责部分文件的抓取 Pcd i  
**FileSplitterFetch.java 11nO<WH  
*/ KFCQYdI`d  
package NetFox; wWp?HDl"M  
tyBg7dP  
F(0pru4u  
import java.io.*; a,en8+r ]  
import java.net.*; #c8"  
C?_t8G./_  
&utS\-;G  
public class FileSplitterFetch extends Thread { @]}Qh;a~  
3hp tP  
P}w^9=;S  
String sURL; //File URL !XG/,)A  
long nStartPos; //File Snippet Start Position o(S^1j5  
long nEndPos; //File Snippet End Position zIX}[l4EW~  
int nThreadID; //Thread's ID 0B#rqTEKu  
boolean bDownOver = false; //Downing is over (7 ]\p  
boolean bStop = false; //Stop identical {Tjtj@-  
FileAccessI fileAccessI = null; //File Access interface *X"F:7  
^MF=,U'8  
>?:i6&4o  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oW\Q>c7 =  
{ r zc 3k~@  
this.sURL = sURL; % B7?l  
this.nStartPos = nStart; _.s\qQ  
this.nEndPos = nEnd; 72B zvY.  
nThreadID = id; +4p2KYO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b*$o[wO9  
} .pNq-T  
&**.naSo  
i&AXPq>`  
public void run() Rqv+N]  
{ 'PxL^  
while(nStartPos < nEndPos && !bStop) 3l41r[\  
{ j:\_*f  
7ZR0M&pX  
/eI,]CB'z  
try{ \f<thd*bC  
URL url = new URL(sURL); '<U[;H9\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0(.R?1*:Rf  
httpConnection.setRequestProperty("User-Agent","NetFox"); .5$V7t.t$\  
String sProperty = "bytes="+nStartPos+"-"; )Uoe ~\  
httpConnection.setRequestProperty("RANGE",sProperty); >u%[J!Y;;  
Utility.log(sProperty); ' ]H#0.  
:7'0:'0$t  
j+ T\c2d  
InputStream input = httpConnection.getInputStream();  T!O3(  
//logResponseHead(httpConnection); cmC&s'/8`D  
TO;]9`~;Mu  
0[3tW[j  
byte[] b = new byte[1024]; Hr_x~n=w  
int nRead; ~>wq;T:=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '!2  
{ 'j =PbA  
nStartPos += fileAccessI.write(b,0,nRead); 4'u|L&ow  
//if(nThreadID == 1) 0v,`P4_k  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YH:W]  
} r>D[5B  
U7Sl@-#|  
%.r5E2'  
Utility.log("Thread " + nThreadID + " is over!"); DrYoC7   
bDownOver = true; 9Y*VzQE  
//nPos = fileAccessI.write (b,0,nRead); <=LsloI  
} 8~XI7g'5x  
catch(Exception e){e.printStackTrace ();} ,YuWz$aF{  
} +HVG5l  
} wNlV_  
'e8d["N  
(Nve5  
//打印回应的头信息 E].a|4sh  
public void logResponseHead(HttpURLConnection con) IcNIuv  
{ l.LFlwt  
for(int i=1;;i++) !&:.Uh  
{ A'P}mrY  
String header=con.getHeaderFieldKey(i); j^R~ Lt4  
if(header!=null) W(3~F2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e?'k[ES^  
Utility.log(header+" : "+con.getHeaderField(header)); . LVOaxT  
else -2m Ogv  
break; F$pd]F!#  
} aABE= 9Y  
} x[h<3V"  
?}>B4Z)  
x[,wJzp\6  
public void splitterStop() H'(o}cn7~  
{ 8`R}L  
bStop = true; bKbpI>;[  
} d%|#m)  
!D]6Cq  
'}[L sU  
} c^/?VmCQ}  
nV6g]#~ @  
g960;waz3  
/* ;|e 0{Jrz  
**FileAccess.java I<o4l[--  
*//文件访问(定位,写) ~+NFWNgN  
package NetFox; \|4MU"ri  
import java.io.*; .J! $,O@  
Q $,kB<M  
j~<iTLM  
public class FileAccessI implements Serializable{ 4)S?Y"Bs  
x>/@Z6Wxz  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nJ`a1L{N  
RandomAccessFile oSavedFile; Yka yT0!  
long nPos; < EE+ S#z  
4%.2 =  
yeh adm\  
public FileAccessI() throws IOException Z.#glmw^=R  
{ G"R>aw  
this("",0); `x^,k% :4  
} 6xQe!d3>s3  
fP4IOlHkE  
t 1'or  
public FileAccessI(String sName,long nPos) throws IOException $@!&ML  
{ ?^A:~"~  
oSavedFile = new RandomAccessFile(sName,"rw"); ,lGwW8$R  
this.nPos = nPos; ?;kc%Rz  
oSavedFile.seek(nPos); =kkA  
} 0BZOr-i  
~5?n&pF  
D&lXi~Z%.  
public synchronized int write(byte[] b,int nStart,int nLen) -D':7!@  
{ 9fLP&v  
int n = -1; h 7P?n.K  
try{ +as\>"Cj+2  
oSavedFile.write(b,nStart,nLen); V$%Fs{  
n = nLen; D,R2wNF  
} Hu!>RSg,,2  
catch(IOException e) 7)X&fV6<8  
{ Q`fA)6U  
e.printStackTrace (); Bc ,z]  
} !6`nN1A  
dK`O,[}  
?26[%%  
return n; 3cQmxp2*  
} EJ|ZZYke!  
!ZcA Ltq  
Cjb p-  
} !ef)Ra-W  
M L_J<|,J  
;SP3nU))  
/* ZQ8Aak  
**SiteInfoBean.java Y2$`o4*3  
*/ 5rSth.&  
package NetFox; 0-O.*Q^  
2xxwQwg8  
\O4=mJ  
public class SiteInfoBean { s,q!(\{Pv  
{oC69n:  
K#yH\fn8  
private String sSiteURL; //Site's URL R')GQ.yYq  
private String sFilePath; //Saved File's Path T$B4DQ  
private String sFileName; //Saved File's Name ~x\ Q\Cxp  
private int nSplitter; //Count of Splited Downloading File @WE$%dr  
mM%BO(X{=  
K\r=MkA.>  
public SiteInfoBean() g9Qxf%}  
{//nSplitter的缺省值为5 nUu|}11(  
//default value of nSplitter is 5 , |B\[0p  
this("","","",5); 7oSuLo=  
} ?2/M W27w  
Bd[}A9O[  
$f\-.7OD  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c>k6i?u:X7  
{ L(rjjkH  
sSiteURL= sURL; |n%N'-el  
sFilePath = sPath; )[Cm*Xxa$  
sFileName = sName; $e\R5L u  
this.nSplitter = nSpiltter; :G)x+0u  
4s2ex{$+MA  
hkc_>F]Hx  
} aB_z4dqwU  
'hWRwP|  
D1/$pA+B  
public String getSSiteURL() =jHy6)6w  
{ NP/2gjp  
return sSiteURL; 51usiOq  
} gQG iph |  
eT?LMBn\  
+t6m>IBu  
public void setSSiteURL(String value) t, YAk ?}  
{ )&-+:u0  
sSiteURL = value; ;sJ2K"c  
} <C xet~x  
W%:zvqg v  
f>PU# D@B  
public String getSFilePath() 7 {<lH%Tn  
{ ]d(}b>gR~(  
return sFilePath; $SgD| 9  
} p.olXP  
:.^rWCL2  
2%H( a)  
public void setSFilePath(String value) #$QY[rf=6  
{ J'v|^`bE  
sFilePath = value; 3E9j%sYk  
} CAO{$<M5m  
MQu6Tm H  
vnpX-c  
public String getSFileName() /y@iaptC  
{ ,B!Qv3bn  
return sFileName; Ss}0.5Bq  
} b@Cvs4  
^5F/=TtE G  
i>}z$'X  
public void setSFileName(String value) )I9(WVx!]  
{ }(6k7{,Gw,  
sFileName = value; mer{Jy s  
} Rl8-a8j$f.  
Pl>t\`1:|A  
:Tl?yG F  
public int getNSplitter() N<WFe5  
{ tDVdl^#  
return nSplitter; Uk4">]oct  
} 8&bj7w,K  
#U6qM(J  
mYvm_t9  
public void setNSplitter(int nCount) <hdCO< 0(  
{ `$HO`d@0*R  
nSplitter = nCount; %cL:*D4oz  
} TMBdneS-s  
} I&c#U+-A'  
on$a]zx'@  
l|{<!7a  
/* v2Y=vr  
**Utility.java ){~.jP=-#  
*/ 1g+<`1=KT  
package NetFox; Yn/-m Z  
1F/&Y}X  
@So"(^  
public class Utility { ~sD'pS  
/j As`"U  
T~Cd=s(T"  
public Utility() ' r/1+.  
{ WDq3K/7\  
ua-p^X`w  
y C#{nUdw  
} 511q\w M  
Heu@{t.[!D  
//线程睡眠 xh$[E&2u  
public static void sleep(int nSecond) b;vO`  
{ l(W3|W#P  
try{ i^(<E0vS  
Thread.sleep(nSecond); oZCO$a  
} HYS7=[hv6  
catch(Exception e) DQd&:J@?  
{ 8*X8U:.0o  
e.printStackTrace (); K"61i:F  
} q!4dK4`#5  
} Wu(GC]lTG  
6gXc-}dp  
//日志 e9hQJ 1{)x  
public static void log(String sMsg) s#ykD{ Z  
{ p*Cbe\  
System.err.println(sMsg); U<x3=P  
} RD^o&VXO  
2#!D"F  
3h&s=e!  
public static void log(int sMsg) Z)<>d.  
{  <_~`)t  
System.err.println(sMsg); cl:YN]BK  
} x8[8z^BV?e  
} QXCI+Fcg  
SL*(ZEn"  
UT-=5  
/* +?8nY.~,'  
**TestMethod.java |8"HTBb\CW  
*/ ofJ@\xS  
package NetFox; J7H1<\=cJb  
ZyG528O22  
wC19  
public class TestMethod { 3c)LBM  
_z;N|Xe  
W$W7U|Z9y+  
public TestMethod() tF 4"28"h  
{ ///xx/weblogic60b2_win.exe z|Xl%8  
try{ LS`Gg7]S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?^5x d1>E  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <q|19fH-5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :3k(=^%G!  
fileFetch.start(); JW$#~"@r  
} BmZd,}{  
catch(Exception e){e.printStackTrace ();} <M=K!k  
$d'Gh2IGA  
<_+8c{G  
} B N=,>-O%  
iH2|w  
{pqm&PB04  
public static void main(String[] args) 8r5j~Df  
{ WE3l*7<@  
new TestMethod(); <H.Ml>q:r  
} Z1&8 U=pax  
} \6o ~ i  
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