http断点续传简单实现（java)

/* ZP)=2'RY  
**SiteFileFetch.java [[D}
vL8d  
*/ HZQI|  
package NetFox; K! /E0G&  
import java.io.*; ./<3jf :  
import java.net.*; F dv&kK!  
)I+1 b !U  
SU# S'  
public class SiteFileFetch extends Thread { |~H'V4)zXu  
5*buRYck0  
oW]&]*>J  
SiteInfoBean siteInfoBean = null; //文件信息Bean =Ak>2  
long[] nStartPos; //开始位置 6@2p@eYo  
long[] nEndPos; //结束位置 af{;4Cr  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !W$3p'8Tu  
long nFileLength; //文件长度 MC#bo{Bq3-  
boolean bFirst = true; //是否第一次取文件 |iM*}Ix-  
boolean bStop = false; //停止标志 v03~=(  
File tmpFile; //文件下载的临时信息 (I.uQP~H  
DataOutputStream output; //输出到文件的输出流 Cu;X{F'H  
q1dYiG.-Z  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） 5, Yk5?l<'  
public SiteFileFetch(SiteInfoBean bean) throws IOException glHag"(  
{ wX 41R]pF  
siteInfoBean = bean; !^axO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); B_5q}Bp<  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Wr)%C  
if(tmpFile.exists ()) >mF
`XbS  
{ Wc3!aLNx  
bFirst = false; |[34<tIN  
read_nPos(); C,PCU<q  
} j{_MDE7N  
else M/V >25`  
{ +G/~v`Bv  
nStartPos = new long[bean.getNSplitter()]; e
^'?:j  
nEndPos = new long[bean.getNSplitter()]; M`?/QU~  
} \f66ipZK*  
ip5s'S~  
/LSiDys  
66L*6O4  
} flLmZ1"  
[RpFC4W  
q/OraPAB  
public void run() cJ8*[H<NV  
{ h]EXD  
//获得文件长度 N[pk@M\vX  
//分割文件 b}"/K$`Fd  
//实例FileSplitterFetch *)]SsM1  
//启动FileSplitterFetch线程 BC
$In!  
//等待子线程返回 s?Q`#qD  
try{ D"x~bs?V\  
if(bFirst) q }z,C{Wq<  
{ zx'`'t4~  
nFileLength = getFileSize(); !;\-V}V  
if(nFileLength == -1) =D[h0U  
{ b1*6)  
System.err.println("File Length is not known!"); c7r
YG]  
} D 0n2r  
else if(nFileLength == -2) &tRnI$D  
{ 3F.O0Vz  
System.err.println("File is not access!"); Gj)Qw6  
} d'3'{C|kk  
else )i!)Tv  
{ SbI,9<  
for(int i=0;i<nStartPos.length;i++) S?3{G@!  
{ k6Tpaf^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); PPq*_Cf  
} Cn`% *w  
for(int i=0;i<nEndPos.length-1;i++) 4x C0Aw  
{ *E. 2R{  
nEndPos = nStartPos[i+1]; e@,L~\  
} Fk9(FOFg  
nEndPos[nEndPos.length-1] = nFileLength; Mvcl9  
} F 1zc4l6  
} 9MYt4  
3p4bOT5  
b5)>h  
//启动子线程 `GDYL7pM(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PRah?|*0s  
for(int i=0;i<nStartPos.length;i++) ?=4t~\g?  
{ &YMVoyVD  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y-{spTI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WI~%n  
nStartPos,nEndPos,i); VmT5?i   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^X;>?_Bk  
fileSplitterFetch.start(); eD(a +El}  
} T]zjJwa  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g1{wxBFE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9E#(iP  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oaXD^H\  
nEndPos = " + nFileLength); sO6t8)$b  
// fileSplitterFetch[nPos.length-1].start(); C9iG`?  
`fV$'u  
#62ww-E~  
//等待子线程结束 T a[74;VO  
//int count = 0; @"EX%v.  
//是否结束while循环 *oWzH_  
boolean breakWhile = false; <?7~,#AK  
X'F$K!o*,:  
o{Ep/O`  
while(!bStop) KW
H  
{ yTvK)4&  
write_nPos(); YOoP]0'L  
Utility.sleep(500); nc{<v  
breakWhile = true; sI'HS+~pU  
5.E 2fX  
a[!d)Y:zx  
for(int i=0;i<nStartPos.length;i++) ;7A,'y4f  
{ "O 'I  
if(!fileSplitterFetch.bDownOver) ;C<A}  
{ n)H0;25L  
breakWhile = false; ;(,Fe/wvC  
break; O:x%!-w  
} e_;6UZ+  
} igL^k`&5^"  
if(breakWhile) /Rz,2jfRx'  
break; 6};oLnO  
o
u-;k }  
/W>"G1)  
//count++; 7L6M#B[)e5  
//if(count>4) ?n+\T'f!  
// siteStop(); q<8HG_  
} Z}C%%2Iz  
aKy|$ {RC  
%G&v@R  
System.err.println("文件下载结束！"); <coCu0  
} jdp:G  
catch(Exception e){e.printStackTrace ();} w6Q]?p+  
} u5ygbCm  
cOgtBEhn  
iy"Kg]  
//获得文件长度 'W*F[U*&HP  
public long getFileSize() rY= #^S  
{ 463dLEd  
int nFileLength = -1; }{y$$X<:  
try{ BSf"'0I&
 
URL url = new URL(siteInfoBean.getSSiteURL()); u\wd<<I']  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iE`aGoA  
httpConnection.setRequestProperty("User-Agent","NetFox"); l:"*]m7o_  
7KIQ)E'kG|  
:[39g;V}c  
int responseCode=httpConnection.getResponseCode(); c53`E U  
if(responseCode>=400) T1&H!  
{ :JIPF=]fc  
processErrorCode(responseCode); *ZGN!0/  
return -2; //-2 represent access is error 0}V'\=F454  
} y<b0z\  
Y5CE#&  
'1 $({{R  
String sHeader; v],DBw9  
6zWvd  
-EaZ<d[|0  
for(int i=1;;i++) 1%`:8  
{ '7R'fhiO/3  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <k6xScy$}  
//Utility.log(in.readLine()); ]IV;>94[
 
sHeader=httpConnection.getHeaderFieldKey(i);
O :^[4$~  
if(sHeader!=null) &/F
[kAy  
{ qI^jwl|k  
if(sHeader.equals("Content-Length")) -c@
5qe>  
{ PgAfR:Y!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ke'2"VkQt  
break; 9iCud6H,h  
} %
5gJ6>@6Z  
} -pu\p-Z  
else tW>R 16zq  
break; B;r$( 'UZ  
} yFo5pKF.J  
} eHe /w9`$R  
catch(IOException e){e.printStackTrace ();} 9Q/!%y%5  
catch(Exception e){e.printStackTrace ();} .*blM1+6i/  
*Rh .s!@4  
!.$P`wKr  
Utility.log(nFileLength); xk8p,>/  
dCTpO  
P0z{R[KBH  
return nFileLength; uLljM{I  
} OvG0UXRU  
*,*qv^  
iGk{8Da<  
//保存下载信息（文件指针位置） {B.]w9  
private void write_nPos() y3]"H(  
{ %ko 8P  
try{ :<8V2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8v 1%H8  
output.writeInt(nStartPos.length); Z-a(3&  
for(int i=0;i<nStartPos.length;i++) yZ$;O0f&&  
{ ?/MXcI(  
// output.writeLong(nPos); ~[q:y|3b  
output.writeLong(fileSplitterFetch.nStartPos); `&zobbwq  
output.writeLong(fileSplitterFetch.nEndPos); |l(lrJ{  
} B31-<w  
output.close(); 
q"<-  
} y(h(mr  
catch(IOException e){e.printStackTrace ();} nF$)F?||  
catch(Exception e){e.printStackTrace ();} ~|C1$.-  
} 
{~g  
iQC&d_#  
ix@rq#  
//读取保存的下载信息（文件指针位置） /exl9Ilt]  
private void read_nPos() *AR<DXEL  
{ E]?HCRa5R  
try{ G5J ZB7C  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $ow`)?sh  
int nCount = input.readInt(); Jjh!/pWZ4  
nStartPos = new long[nCount]; / i2-h  
nEndPos = new long[nCount]; H)aC'M^
 
for(int i=0;i<nStartPos.length;i++) an[~%vxw}  
{

d|+jCTKS  
nStartPos = input.readLong(); ?Hxgx  
nEndPos = input.readLong(); 8z8SwWS?  
} G0Tc}_o<Y  
input.close(); :vyf-K74M  
} @b\_696.  
catch(IOException e){e.printStackTrace ();} To%*)a  
catch(Exception e){e.printStackTrace ();} 'N ::MN  
} T)tHN#6I  
pbxcsA\  
Lj-&TO}OZ  
private void processErrorCode(int nErrorCode) |Umfq:W`y_  
{ DB'KIw  
System.err.println("Error Code : " + nErrorCode); x0$:"68PW  
} 6ilC#yyp  
]J=)pDrk  
/1#Q=T  
//停止文件下载 xWe1F2nY  
public void siteStop() vP)~j1  
{ Rn_W|"  
bStop = true; lT!$\E$1   
for(int i=0;i<nStartPos.length;i++) B5H&DqWzr  
fileSplitterFetch.splitterStop(); wK`ieHmp  
Bp{`%86SE  
7+hF;  
} YGV#.  
} `$agM@"^  
//负责部分文件的抓取 'Qq_Xn8  
**FileSplitterFetch.java cPaWJ+c  
*/ 9Y@?xn.\  
package NetFox; !Fg4Au  
J}_Dpb[L  
N?{1'=Om  
import java.io.*; :`^3MMLO  
import java.net.*; =*:_swd  
yO,`"Dc_0  
v;}`?@G  
public class FileSplitterFetch extends Thread { {!eANm'  
mS~
]I$  
{AL9o2  
String sURL; //File URL 5h=TV  
long nStartPos; //File Snippet Start Position ck
_fEF  
long nEndPos; //File Snippet End Position kxqc6  
int nThreadID; //Thread's ID 8u5 'g1M  
boolean bDownOver = false; //Downing is over N|O]z  
boolean bStop = false; //Stop identical ?-::{2O)  
FileAccessI fileAccessI = null; //File Access interface 3)c K*8#  
SM#S/|.]  
u6Qf*_-K  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {+6D-rDw  
{ }wOpPN[4  
this.sURL = sURL; fxoi<!|iGY  
this.nStartPos = nStart; t-7U1B}=<C  
this.nEndPos = nEnd; 6+B{4OY  
nThreadID = id; "$IXZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /sT ^lf=  
} cI%"Ynq"3  
Q6!v3P/h  
6;[/9  
public void run() 1S(\2{Ylo  
{ 7Cd_zZ  
while(nStartPos < nEndPos && !bStop) X:``{!~geo  
{ uQu/(5  
>g>`!Sf  
E_D ^O  
try{ ]dbSa1?  
URL url = new URL(sURL); ~@4ZV  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6%\Q*r*N  
httpConnection.setRequestProperty("User-Agent","NetFox"); l/png:  
String sProperty = "bytes="+nStartPos+"-"; T<f\*1~^  
httpConnection.setRequestProperty("RANGE",sProperty); Z 5)_B,E:X  
Utility.log(sProperty); ,c%K)KuPK.  
Vl 19Md  
95^i/6Gl!P  
InputStream input = httpConnection.getInputStream(); Gkv~e?Kc~^  
//logResponseHead(httpConnection); VwOG?5W/  
puS&S *  
m UWkb  
byte[] b = new byte[1024]; hP1 l v7P  
int nRead; B?#kW!wj  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bKuj po6  
{ C3\E.u?  
nStartPos += fileAccessI.write(b,0,nRead); "7yNKO;W  
//if(nThreadID == 1) &`yOIX-H_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GT'7,+<?N  
} H\| ]!8w5Z  
\/*Nf?;  
'cAc{\)  
Utility.log("Thread " + nThreadID + " is over!"); BU9J_rCIv  
bDownOver = true; :/v,r=Y9p  
//nPos = fileAccessI.write (b,0,nRead); )XP#W|;  
} 2<'`^AO@  
catch(Exception e){e.printStackTrace ();} $Eio$TI  
} 3T|Y}  
} `s`C{|wv  
)_77>f
%  
G`,u40a  
//打印回应的头信息 h@~:(:zU$  
public void logResponseHead(HttpURLConnection con) Il{^ j6  
{ [6; N3?+  
for(int i=1;;i++) ]^:hyOK  
{ g/8.W  
String header=con.getHeaderFieldKey(i); $s-9|Lbs`  
if(header!=null) S~0JoCeo  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u R\m`  
Utility.log(header+" : "+con.getHeaderField(header)); PMgQxM*h  
else =n-z;/NL  
break; xMDrE?  
} *
O@sh  
} 4E=0qbt8  
P_p6GT:5  
Ys-Keyg  
public void splitterStop() >1x7UXs~:  
{ )Fqy%uR8  
bStop = true; r8uqcKfU  
} 5-D`<\  
iOT)0@f'  

d5
DP^u  
} KNg8HYFW\  
1GtOA3,~;-  
c 9rVgLqn!  
/* ?ork^4 $s  
**FileAccess.java %O#)Nq>mp  
*//文件访问(定位，写) )YuRjBcp,"  
package NetFox; fNkuX-om  
import java.io.*; C"6Amnj  
L@w0N)P<!{  
ngP7'1I  
public class FileAccessI implements Serializable{ _6;<ow  
*B0V<mV  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 </.z1 $  
RandomAccessFile oSavedFile; z|ves&lRa  
long nPos; cDCJ]iDs  
d,
W/M(S  
,I]7g4~  
public FileAccessI() throws IOException v btAq^1  
{ RC
zV5g  
this("",0); $[,l-[-+  
} D7)(D4S4  
B4Q79gEh=  
KiQ(XNx  
public FileAccessI(String sName,long nPos) throws IOException q"S(7xWS  
{ 9"~9hOEct  
oSavedFile = new RandomAccessFile(sName,"rw"); (]2<?x*  
this.nPos = nPos; Hk,lX
r  
oSavedFile.seek(nPos); j"5Pe  
} xw?CMA  
J"-_{)0lD  
v"rl5x  
public synchronized int write(byte[] b,int nStart,int nLen) vF"c  
{ 5^yG2&>#  
int n = -1; )o{VmXe@@  
try{ yVaUt_Zi  
oSavedFile.write(b,nStart,nLen); hp*<x4%*a"  
n = nLen; rJu[N(2k  
} "Nbos.a]5  
catch(IOException e) Yv^p=-E  
{ !Cw!+fZ\l  
e.printStackTrace (); *vYn_wE  
} MSl&?}Bj  
qU#$2  
``!GI'^  
return n; V]rhVMA  
} NCi>S%pD`<  
_?.\Xc  
Pey//U  
} ]u+MTW;  
m4@MxQm  
/}=a{J  
/* 4d0#86l~J/  
**SiteInfoBean.java tRteyNA  
*/ NvQ%J+  
package NetFox; .)7:=  
LP9)zi  
-ui<E?v  
public class SiteInfoBean { G
Mb(10T`  
&UL_bG}  
l4KbTKm7  
private String sSiteURL; //Site's URL Hd*}k6  
private String sFilePath; //Saved File's Path nd:E9:  
private String sFileName; //Saved File's Name EWA;L?g|A  
private int nSplitter; //Count of Splited Downloading File Ea4_Qmn  
K#!X><B
'  
r,4lqar;E  
public SiteInfoBean() 4=xq:Tf  
{//nSplitter的缺省值为5 `B:"6nW6  
//default value of nSplitter is 5 A2NF<ZsD  
this("","","",5); -f?Ah  
} *"cD.)]#2  
XKqK<!F  
MS*G-C  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z19m@vMsIP  
{ @*(4dt:V  
sSiteURL= sURL; ]CX[7Q
+'  
sFilePath = sPath; |CIC$2u  
sFileName = sName; f@@s1gdb  
this.nSplitter = nSpiltter; y\'P3ihK  
\~#WY5  
EB!daZH,  
} 7J|&U2}c  
|TTS?  
Gr: 3{o`  
public String getSSiteURL() x6;j<m5Mjx  
{ g?G+dnl/8  
return sSiteURL; J#Z5^)$  
} zE|Wn3_sd  
c2*`2qK#  
7LCp7$Cp  
public void setSSiteURL(String value) ]6&$|2H?Ni  
{ mI7~c;~  
sSiteURL = value; 9JshMo  
} #??%B  
PB9/m-\H  
uP@\#/4u  
public String getSFilePath() 2r&R"B1`(  
{ "NzD1k6.L  
return sFilePath; V*RdDF7  
} }T.?c9l X  
?D|\]0eN  
fP[& a9l  
public void setSFilePath(String value) !%PWig-  
{ |c2xy  
sFilePath = value; B4ZIURciGz  
} T6M+|"92  
S1J<9xqSQ8  
XIAeCU  
public String getSFileName() Quzo8u  
{ p $ouh  
return sFileName; lA^+Flh  
}
,=BLnsg  
.Cz %:%9  
* R d#{Io7  
public void setSFileName(String value) 2p!"p`b~  
{ W^\d^)  
sFileName = value; `t(D!  
} vq!uD!lr  
A8DFm{})c  
3yA2WW  
public int getNSplitter() ,v9f~qh  
{ 7N=-Y>$X  
return nSplitter; ROc`BH=  
} -#s [F S  
j_cs;G: "  
hs+kr?Pg`  
public void setNSplitter(int nCount) ycAKK?O*  
{ PdeBDFWD  
nSplitter = nCount; =ll=)"O  
} -\,zRIOK  
} p'94SXO_  
(%_n!ip^  
a%vrt)Gx  
/* nFRsc'VT  
**Utility.java :5fAPK2r<  
*/ l2jF#<S@  
package NetFox; ihCIh6  
!CUoHTmB  
TsQU6NNE  
public class Utility { nV_8Ke  
d3;qsUh$yv  
x=Hndx^  
public Utility() Q.U$nph\%d  
{ I+(/TP  
M*eJ JY  
3oy~=  
} OJAIaC\  
EZD
y+6b  
//线程睡眠 S9| a$3K'  
public static void sleep(int nSecond) 6Jz^  
{ Li
QgR 6j  
try{ I5m][~6.?  
Thread.sleep(nSecond); ~b~2 >c9  
} ;gg\;i}^  
catch(Exception e) 13hE}g;.  
{ K(}AX+rIg  
e.printStackTrace (); ?sz)J3  
} dt}_D={Be  
} Zw1U@5}A  
M]]pTU((  
//日志
#/2$+x  
public static void log(String sMsg) t2HJsMX  
{ XFVV},V  
System.err.println(sMsg); lj=l4 &.i  
} *l&S-=]  
5Por "&%  
]b/S6oc6  
public static void log(int sMsg) m!tx(XsXU  
{ Z3TS,a1I4  
System.err.println(sMsg); Ev"|FTI/  
} \55VqGyxu9  
} Vr[czfROz'  
_nh[(F<hz  
yp.[HMRD  
/* kX`[Y@nUN  
**TestMethod.java j
=?'4sF  
*/ SMH
<'F7i  
package NetFox; ao_4mSB  
jnB~sbyA  
EZ;"'4;W  
public class TestMethod { :#k &\f-Y  
#|GSQJ$F)`  
nrm+z"7  
public TestMethod() q#w8wH"  
{ ///xx/weblogic60b2_win.exe gKz(=  
try{ $dS@y+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zq+o+o>xo  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u9+kLepOT  
SiteFileFetch fileFetch = new SiteFileFetch(bean); uDw.|B2ui  
fileFetch.start(); yXI >I
 
} 'H8(=9O1d  
catch(Exception e){e.printStackTrace ();} \s"U{N-  
8K(Z0  
F!zP<A"  
} >MK>gLg}!  
=@2FX&&E_  
7>XDNI  
public static void main(String[] args) c;0Vs,DUmG  
{ .MQ^
(  
new TestMethod(); Wq*b~Lw  
} &k-Vcrcz  
} H{J'# 9H  
点击下载更多相关资料