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http断点续传简单实现(java)

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/* \Dl MOG  
**SiteFileFetch.java 4-HBXG9#/  
*/ j0"4X  
package NetFox; 3 }sy{Mx%9  
import java.io.*; m2~`EL>  
import java.net.*; LRw-I.z  
B4HMs$>   
,f%4xXI  
public class SiteFileFetch extends Thread { d_:f-  
A;X3z-[[  
I] +OYWp  
SiteInfoBean siteInfoBean = null; //文件信息Bean Zk~Pq%u  
long[] nStartPos; //开始位置 ^d# AU7V|  
long[] nEndPos; //结束位置 tSni[,4Kq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QeT~s5 H  
long nFileLength; //文件长度 HoX={^aG%  
boolean bFirst = true; //是否第一次取文件 ;9#%E  
boolean bStop = false; //停止标志 'k}w|gNB  
File tmpFile; //文件下载的临时信息 'I}wN5`  
DataOutputStream output; //输出到文件的输出流 ;d fIzi  
e34g=]"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :RDk{^b)  
public SiteFileFetch(SiteInfoBean bean) throws IOException p<pGqW  
{ 1fV)tvU$  
siteInfoBean = bean; OZz/ip-!lc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Zcw <USF8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); fHwS12SB  
if(tmpFile.exists ()) OK-*TPrc  
{ 5{!"}  
bFirst = false; YHY*dk*|C  
read_nPos(); yzl}!& E  
} ve"tbNL  
else mQt0?c _  
{ 'xG{q+jj'  
nStartPos = new long[bean.getNSplitter()]; Pxkh;:agD  
nEndPos = new long[bean.getNSplitter()]; 4K HIUW$  
} w`< {   
@+ T33X)h%  
O9<oq  
Gh6U<;V?*  
} ?Vh#Gr  
~-G_c=E?  
+2p}KpOsL  
public void run() FWp ?l  
{ ^Nds@MR{8'  
//获得文件长度 F_ -Xx"  
//分割文件 1Ke9H!_P  
//实例FileSplitterFetch dEI!r1~n  
//启动FileSplitterFetch线程 *>:<  
//等待子线程返回 yK"HHdYTV  
try{ "9X!Ewm"P  
if(bFirst) 0dsL%G~/N  
{ RH7!3ye  
nFileLength = getFileSize(); zFDtC-GF  
if(nFileLength == -1) lSoAw-@At8  
{ B@z ng2[  
System.err.println("File Length is not known!"); <e S+3,  
} OXl0R{4  
else if(nFileLength == -2) MOytxl:R  
{ ^R :zma  
System.err.println("File is not access!"); oO7)7$|1  
} ang~_Ec.  
else }Q\+w,pJgN  
{ YUTh*`1k<  
for(int i=0;i<nStartPos.length;i++) pVzr]WFx  
{ }G^'y8U  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); m$hkmD|  
} '~7zeZ'  
for(int i=0;i<nEndPos.length-1;i++) ?I+$KjE+  
{ 6Hy_7\$(-  
nEndPos = nStartPos[i+1]; 0"GLgj:9  
} $Fi1Bv)  
nEndPos[nEndPos.length-1] = nFileLength; b?!S$Sxz  
} S{)K_x  
} ^xScVOdP  
L&=r-\.ev  
u(hJyo}  
//启动子线程 0N]\f.=`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GjN6Af~}  
for(int i=0;i<nStartPos.length;i++) 92C; a5s  
{ 7hLh}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >o3R~ [  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4MzPm~Ct  
nStartPos,nEndPos,i); }}rp/16  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j0Cj&x%qF}  
fileSplitterFetch.start(); zN)).a  
} Ek_<2!%X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '-XO;{,-R  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C CLc,r>)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UUvCi+W  
nEndPos = " + nFileLength); bVa?yWb.  
// fileSplitterFetch[nPos.length-1].start(); .kkhW8:  
6]?W&r|0I  
KW ZEi?  
//等待子线程结束 jS8B:>  
//int count = 0; [#G*GAa6*  
//是否结束while循环 ^wwS`vPb  
boolean breakWhile = false; @Jqo'\~&  
M0?%r`  
ly_8p63-  
while(!bStop) A>mk0P)~Q  
{ LylCr{s7  
write_nPos(); 8\C][ y  
Utility.sleep(500); _ShWCU-~Z  
breakWhile = true; <c<!|<x  
fz8 41 <Y  
B~@Gfb>`'  
for(int i=0;i<nStartPos.length;i++) .A_R6~::  
{ @SaxM4  
if(!fileSplitterFetch.bDownOver) ;n|%W,b-  
{ &m\Uc  
breakWhile = false; oSjYp(h:  
break; 0ZLLbEfnPB  
} 4pelIoj  
} u]`0QxvZ  
if(breakWhile) yh|+Usa  
break; 9:=:P>  
3^$=XrD  
Bc-/s(/Eq  
//count++; kkMChe};5  
//if(count>4) m6}_kzFz  
// siteStop(); {.;qz4d`  
} 3` D['  
N_Zd.VnY  
%~>-nqS  
System.err.println("文件下载结束!"); E`C !q X>  
} Oz&*A/si+3  
catch(Exception e){e.printStackTrace ();} 5DkEJk7a  
} "3a}~J<g  
V,8Z!.MG  
:>_oOn[_  
//获得文件长度 *DZ7,$LQ~D  
public long getFileSize() [7LdTY"Tl  
{ D,lY_6=  
int nFileLength = -1; &h!O<'*2  
try{ 4}UJ Bb?  
URL url = new URL(siteInfoBean.getSSiteURL()); F0r2=f(?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zw'050~-  
httpConnection.setRequestProperty("User-Agent","NetFox"); agkKm?xIL  
7|_2@4-W6  
Z#^|h0  
int responseCode=httpConnection.getResponseCode(); !;d>}iE   
if(responseCode>=400) &#gh :5  
{ JR&yaOws  
processErrorCode(responseCode); 5v`lCu]  
return -2; //-2 represent access is error :)T*:51{#  
} D:z_FNN  
R?tjobk!  
+ 660/ e8N  
String sHeader; UlNV%34"  
m I:^lp  
R7!v=X]i  
for(int i=1;;i++) M`@ASL:u  
{ Xh3b=i|K  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @0C[o9  
//Utility.log(in.readLine()); CPeu="[  
sHeader=httpConnection.getHeaderFieldKey(i); NpKyrXDJv  
if(sHeader!=null) dD~H ft  
{ WU@_aw[  
if(sHeader.equals("Content-Length")) c5 AaUza  
{ Q"c/]Sk)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z5*(xony0  
break; N[fwd=$\#  
} xirq$sEl  
} M&gi$Qs[E  
else T/ eX7p1  
break; WSv%Rxr8L  
} $;~YgOVZ5  
} P|p X F~  
catch(IOException e){e.printStackTrace ();} )`ixT)   
catch(Exception e){e.printStackTrace ();} C@zG(?X  
rl$"~/ oz  
:O,r3O6  
Utility.log(nFileLength); CF\wR;6k  
ue@W@pj  
jt9- v-  
return nFileLength; >ke.ZZV?  
} oR,zr  
_iEnS4$A8  
;volBfv  
//保存下载信息(文件指针位置) }; M@JMu,  
private void write_nPos() rwio>4=  
{ $/@  L  
try{ ZJF+./vN  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `g)  
output.writeInt(nStartPos.length); B*Om\I  
for(int i=0;i<nStartPos.length;i++) HVhd#Q;  
{ UugR  
// output.writeLong(nPos); BSB&zp  
output.writeLong(fileSplitterFetch.nStartPos); q bCU&G|)  
output.writeLong(fileSplitterFetch.nEndPos); f1elzANy  
} PlK3;  
output.close(); 7zA+UWr  
} =PNkzFUo  
catch(IOException e){e.printStackTrace ();} l?V#;  
catch(Exception e){e.printStackTrace ();} A"s?;hv\fS  
} gu~R4 @3  
B.;@i;7L  
3^-R_  
//读取保存的下载信息(文件指针位置) @ uN+]e+3  
private void read_nPos() >H5t,FfQL  
{ ocMTTVo  
try{ kzNRRs\e  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KK4e'[Wf  
int nCount = input.readInt(); (!J;g|58  
nStartPos = new long[nCount]; 7 b(  
nEndPos = new long[nCount]; YjJ^SU`*  
for(int i=0;i<nStartPos.length;i++) Q-#<{' (  
{ H+]h+K9\7  
nStartPos = input.readLong(); 3/uvw>$  
nEndPos = input.readLong(); LHu  
} 5JK'2J&  
input.close(); %g89eaEZ  
} B!8X?8D  
catch(IOException e){e.printStackTrace ();} eH!V%dX  
catch(Exception e){e.printStackTrace ();} {D :WXvI  
} !<VP[%2L~  
|%fNLUJ)  
*A8Et5HAv  
private void processErrorCode(int nErrorCode) l{ql'm  
{ :RJo#ape  
System.err.println("Error Code : " + nErrorCode); j6$@vA)  
} _3wK: T{:  
*:"60fkoU  
e 8oAGh"  
//停止文件下载 $>uUn3hSx\  
public void siteStop() 4K dYiuz0`  
{ !$ii*}  
bStop = true; =h +SZXe<r  
for(int i=0;i<nStartPos.length;i++) }Qe(6'l_  
fileSplitterFetch.splitterStop(); K ;]dZ8  
+ @|u8+  
W/WP }QM  
} N;BuBm5K  
} 1>Vq<z  
//负责部分文件的抓取 ?m7i7Dz   
**FileSplitterFetch.java T /IX(b'<  
*/ H"k\(SPVS  
package NetFox; 4g}r+!T  
92.Rjz;=9?  
eT5IL(mH  
import java.io.*; H\E%.QIx  
import java.net.*; ?"<m{,yQI  
*zDDi(@vtK  
M5dEZ  
public class FileSplitterFetch extends Thread { -MsL>F.]  
FwHqID_!:l  
"lC>_A  
String sURL; //File URL "Ms{c=XPK  
long nStartPos; //File Snippet Start Position ?u".*!%  
long nEndPos; //File Snippet End Position ;;XY&J  
int nThreadID; //Thread's ID bwP@}(K  
boolean bDownOver = false; //Downing is over [cZ/)tm  
boolean bStop = false; //Stop identical ) R5j?6}xF  
FileAccessI fileAccessI = null; //File Access interface .0gfP4{1{  
*=v%($~PK6  
w^ofH-R/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aaN/HE_  
{ .3n\~Sn  
this.sURL = sURL; i O?f&u  
this.nStartPos = nStart; `,/5skeJ  
this.nEndPos = nEnd; f\q5{#"z  
nThreadID = id; L]"$d F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b\o>4T  
} < .e4  
3fXrwmBT8  
1q5S"=+W[  
public void run() Q8QB{*4  
{ vdB2T2F  
while(nStartPos < nEndPos && !bStop) i^Jw`eAmT  
{ F^%\AA]8  
P O0Od z  
m$(OQ,E  
try{ Mw-L?j0o[k  
URL url = new URL(sURL); W?P4oKsql*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4${3e Sg_  
httpConnection.setRequestProperty("User-Agent","NetFox"); _5(p=Zc  
String sProperty = "bytes="+nStartPos+"-"; "$K]+0ryG<  
httpConnection.setRequestProperty("RANGE",sProperty); Z1+Ewq3m  
Utility.log(sProperty); O{7#Xj :_  
3vAP&i'I  
*b 0z/ 6  
InputStream input = httpConnection.getInputStream(); z j#<X  
//logResponseHead(httpConnection); @|">j#0  
V lO^0r^z  
be]/ROP>H  
byte[] b = new byte[1024]; sKR%YK "A  
int nRead; KHC Fz  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  AW|SD  
{ "iX\U'`  
nStartPos += fileAccessI.write(b,0,nRead); 0:4>rYBC   
//if(nThreadID == 1) _K'Y`w']  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \+Y=}P>  
} 0c!^=(  
KD+&5=Y  
`_ M+=*}  
Utility.log("Thread " + nThreadID + " is over!"); 4oryTckS  
bDownOver = true; Iw( wT_  
//nPos = fileAccessI.write (b,0,nRead); Knb(MI6  
} b2[U3)|oO  
catch(Exception e){e.printStackTrace ();} OkISR j'!U  
} IuAu_`,Ndi  
} Fn4yx~0  
O:T 49:R}r  
|*h{GX.(  
//打印回应的头信息 |]?W`KN0  
public void logResponseHead(HttpURLConnection con) 8f)pf$v`   
{ -wl&~}%M  
for(int i=1;;i++) dV'^K%#  
{ eX}aa0  
String header=con.getHeaderFieldKey(i); /?XI,#j3kM  
if(header!=null) \Zx&J.D  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EL z5P}L6  
Utility.log(header+" : "+con.getHeaderField(header)); Ars*H,9>e  
else f2SJ4"X  
break; s?->2gxhx  
} Y+vIU*O  
} +\&6Zbn  
i`];xNR'  
O<,\ tZ'N  
public void splitterStop() @]2aPs} }6  
{ 'o0o.&/=  
bStop = true; yIngenr$  
} xSlgq|8  
2|B@s3a  
8<C@I/  
} $9X?LGUz  
v JVh%l+  
}''0N1,/  
/* NYG!\u\Rm  
**FileAccess.java :5T=y @  
*//文件访问(定位,写) ~EXCYUp4v  
package NetFox; X !0 7QKs  
import java.io.*; F  Qk  
S'ms>ZENC  
S0:Oep   
public class FileAccessI implements Serializable{ k&f/f  
]F>#0Rdc  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CAom4 Sp'  
RandomAccessFile oSavedFile; {TJBB/B1  
long nPos; `D=`xSEYl  
UhkL=+PD  
O#O"]A  
public FileAccessI() throws IOException `T7TWv"M  
{ `l.bU3C  
this("",0); /0fsn_  
} ;E.f%   
n$7*L9)(C  
NW3qs`$-(  
public FileAccessI(String sName,long nPos) throws IOException 8+".r2*_iO  
{ fB,eeT1v?h  
oSavedFile = new RandomAccessFile(sName,"rw"); $ywROa]  
this.nPos = nPos; 0a<h,s0"2  
oSavedFile.seek(nPos); 8tna<Hx  
} /7p(%vr  
41+WIa L  
l`:u5\ rM  
public synchronized int write(byte[] b,int nStart,int nLen) 1ZYo-a;)  
{ Ej6ho0_  
int n = -1; @)[8m8paV  
try{ R)*l)bpZ#  
oSavedFile.write(b,nStart,nLen); p$jAq~C  
n = nLen; >b5 ;I1o=y  
} g"Ueo'd*  
catch(IOException e) c$BH`" <*  
{ HJym|G>%?  
e.printStackTrace (); BtKor6ba  
} XD0a :T)  
6Uq;]@k%  
4(oU88 z  
return n; ;~d$O M  
} 9^?muP<A  
^q& |7Ou-  
PE/uB,Wl  
} P?n4B \!  
^EkxZ4*g  
5jwv!L<n  
/* bqA`oRb\  
**SiteInfoBean.java H<<t^,E^.t  
*/ mT UoFXX[  
package NetFox; &=n/h5e0t&  
%xQ'i4`  
2e-bt@0t  
public class SiteInfoBean { <%m1+%mA.  
!7)#aXt&  
ANM=:EtP  
private String sSiteURL; //Site's URL /QVwZrch  
private String sFilePath; //Saved File's Path K\8zhY  
private String sFileName; //Saved File's Name Qo^(r$BD  
private int nSplitter; //Count of Splited Downloading File I_Gz~qk6  
mD&I6F[s  
%eIaH!x:  
public SiteInfoBean() 74:~F)BP  
{//nSplitter的缺省值为5 rKFnivGT  
//default value of nSplitter is 5 $M!iQ"bb  
this("","","",5); w4}Q6_0v  
} K{`R`SXD  
q+*\'H>  
P 6La)U`VA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xfI0P0+  
{ yE,qLiH  
sSiteURL= sURL; ,c?( |tF  
sFilePath = sPath; $ xHtI]T  
sFileName = sName; ^E8qI8s  
this.nSplitter = nSpiltter; q 165S  
OgC,oj,!/  
(EosLn h0  
} 8-k`"QI=  
^ +@OiL>&i  
kN{$-v=K  
public String getSSiteURL() ISK 8t  
{ h!|Uj  
return sSiteURL; P:vp/x!  
} @H4]Gp ]  
fsw[ R0B  
\f(zMP  
public void setSSiteURL(String value) E"S# d&9  
{ |o9`h9i  
sSiteURL = value; u7RlxA:  
} w%iw xo   
`sso Wn4  
W}3%BWn  
public String getSFilePath() } eHxw+.  
{ S$$SLy:P  
return sFilePath; #Ktk["6  
} L97 ~ma  
:3 Hz!iZM  
2PRiiL@  
public void setSFilePath(String value) >JsVIfAF  
{ Z}\,rex  
sFilePath = value; _&9P&Zf4  
} [TUs^%2@  
<;?1#ok  
~xsJML  
public String getSFileName() ISFNP&& K  
{ esBv,b?*  
return sFileName; !u8IZpf  
} S5ai@Ks f  
{,h_T0D^j  
bfZt<-  
public void setSFileName(String value) ~]d9 J  
{ JA9NTu(  
sFileName = value; jXALL8[c  
} D&ua A-;s  
&S 66M2  
aQ\SV0PI  
public int getNSplitter() h%W,O,K/  
{ ji\LC%U-  
return nSplitter; rXMc0SPk  
} z\ONw Ml  
|nnFjGC`~  
V V}"zc^  
public void setNSplitter(int nCount) f+s)A(?3  
{ #V]8FW  
nSplitter = nCount; |gu@b~8  
} _b-g^#L%  
} Qb>("j~Z  
r2'K'?T3  
w@Q~ax/  
/* x4wTQ$*1  
**Utility.java u pUJF`3  
*/ O#18a,o@  
package NetFox; }s@IQay+  
*C+[I  
?Sa,n^b*H  
public class Utility { J(/J;PW  
y }R2ZO  
wXqwb|2  
public Utility() iV?8'^  
{ YzM/?enK}T  
:{Z%dD  
" j?xgV  
} !> +Lre@  
%5KK#w "  
//线程睡眠 lt:&lIW,3  
public static void sleep(int nSecond) N}7b^0k  
{ 0n`Temb/  
try{ sH2xkUp  
Thread.sleep(nSecond); XP%_|Q2X  
} 7_qsVhh]$E  
catch(Exception e) |ZifrkD=  
{ =1R 2`H\  
e.printStackTrace (); =LK`m NA  
} .B2e$`s$  
} M!!vr8}  
^q/^.Gf  
//日志 ,P`GIGvkA  
public static void log(String sMsg) ^b|? ?9&  
{ SIR2 Kc0  
System.err.println(sMsg); ~p n$'1Q  
} MoEh25U.  
M.MQ?`_"b  
" a'I^B/  
public static void log(int sMsg) N: 38N  
{ o~9*J)X5i  
System.err.println(sMsg); i>CR{q  
} Ti0kfjhX7  
} !.O[@A\.-  
K,|3?CjS  
GIpYx`mHi  
/* y&8`NS#_p?  
**TestMethod.java -@#],s7  
*/ xy!E_CuC$  
package NetFox; 1(# H%  
,Fkq/h  
#`%S[)RT  
public class TestMethod { A=|a!N/  
P(8 uL|^  
|P|2E~[r  
public TestMethod() &Fuk+Cu{  
{ ///xx/weblogic60b2_win.exe Zj ` ;IYFG  
try{ f B]2"(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xele;)Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aCQ[Uc<B:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); /`aPV"$M  
fileFetch.start(); t4:/qy  
} 7zE1>.  
catch(Exception e){e.printStackTrace ();} m zoH$@  
=X[?d/[  
!XI9evJw  
} s!D2s2b9e  
fQ!W)>mi  
u0oTqD?  
public static void main(String[] args) T>#~.4A0  
{ BOM0QskLf  
new TestMethod(); ,d_rK\J  
} N!dBF t"  
} $qZ6i  
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