http断点续传简单实现（java)

/* D}Sww5ZmP  
**SiteFileFetch.java 3 FV -&Y  
*/ l>KkAA
 
package NetFox; GxEShSGOE  
import java.io.*; 6@eF|GoP  
import java.net.*; {8h[
Bd  
Xj~%kPe  
gtePo[ZH.P  
public class SiteFileFetch extends Thread { 5{
bc&?"  
y G3aF(  
ZJ.a
n%4  
SiteInfoBean siteInfoBean = null; //文件信息Bean !F.h+&^D
;  
long[] nStartPos; //开始位置 T5z]=Pd"^  
long[] nEndPos; //结束位置 }1W@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {Ay dt8  
long nFileLength; //文件长度 %D5F7wB  
boolean bFirst = true; //是否第一次取文件 @\o"
zU  
boolean bStop = false; //停止标志 6?;z\AP&  
File tmpFile; //文件下载的临时信息 aYDo0?kF'  
DataOutputStream output; //输出到文件的输出流 t"Ah]sD  
M:b#">M  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） Fk^N7EJ:$  
public SiteFileFetch(SiteInfoBean bean) throws IOException !&9(D^  
{ .6xMLo,R  
siteInfoBean = bean; mEsb_3?#+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Od)y4nr3~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {ywwJ  
if(tmpFile.exists ()) 8|)^m[c&  
{ *BdH &U  
bFirst = false; x7U=1y(  
read_nPos(); P_w4 DU  
} w"wW0uE^  
else fBj)HoHQW  
{ I<ohh`.  
nStartPos = new long[bean.getNSplitter()]; kD
MvTVd  
nEndPos = new long[bean.getNSplitter()]; IEMa/[n/  
} sQac%.H;`U  
%l
!?d`?  
V5z2.} 'o-  
#[bL9R5NC  
} 8hD[z}  
UaF~[toX  
.8u
@/f%pV  
public void run() V<J1.8H  
{ bo/9k 4N3  
//获得文件长度 %,_ZVgh0  
//分割文件 2&>t,;v@  
//实例FileSplitterFetch C| ~A]wc=  
//启动FileSplitterFetch线程 ~x\uZ^:  
//等待子线程返回 >&KH!:OX|  
try{ 9<.O=-1~  
if(bFirst) [
gMn  
{ e;"J,7@  
nFileLength = getFileSize();
E|"SMA,  
if(nFileLength == -1) KE~Q88s  
{ i7XY3yhC  
System.err.println("File Length is not known!"); M7cD!s@'I  
} g"1V]  
else if(nFileLength == -2) Sv{n?BYq  
{ EXCE^Vw  
System.err.println("File is not access!"); #Az#_0=  
} k`8O/J  
else 5MaN {*)l  
{ -je} PwT  
for(int i=0;i<nStartPos.length;i++) z
&amYwQcI  
{ tr[}F7n9  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); AAlc %d/9  
} x2"1,1%H7  
for(int i=0;i<nEndPos.length-1;i++) rM,e$  
{ ,s#~00C|  
nEndPos = nStartPos[i+1]; E5n7 <
 
} $qQYxx@  
nEndPos[nEndPos.length-1] = nFileLength; ]O"f%  
} r6Yd"~
n  
} I"88O4\@  
LBCH7@V1yR  
l5{60$g  
//启动子线程 at
_*Zh(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G|rE\h 2w  
for(int i=0;i<nStartPos.length;i++) 5p[}<I{  
{ LUMbRrD-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PlzM`g$A  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CW &z?Bra  
nStartPos,nEndPos,i); *#XZ*Ga  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PR.3EL  
fileSplitterFetch.start(); 2F:qaz  
} ~V8z%s@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )y,^M3$?C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2CzhaO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \"a{\E,{;  
nEndPos = " + nFileLength); M,]|L ch  
// fileSplitterFetch[nPos.length-1].start();
QM0B6F  
eIkKsgr>  
5g7@Dj,.  
//等待子线程结束 JI5o~;}m  
//int count = 0; @(,1}3s  
//是否结束while循环 LORcf1X/  
boolean breakWhile = false; 8F}drK9>F  
F^u12R)  
!RI _Uph  
while(!bStop) YExgUE|  
{ (I>Ch)'  
write_nPos(); h !^= c  
Utility.sleep(500); Tlw'05\{J  
breakWhile = true; =fcg4h5(  
cV+?j}"*+  
h:?^0b!@  
for(int i=0;i<nStartPos.length;i++) 4@PA+(kvS  
{ yH/A9L,Z  
if(!fileSplitterFetch.bDownOver) |\,OlX,  
{ RxP H[7oZ  
breakWhile = false; -'&/7e6>y  
break; <CyU9`ye  
} za_b jE  
} N6Mr#A-{  
if(breakWhile) X94a
  
break; !zA@{gvEc  
'FErk~}/4s  
y}?|+/ dN  
//count++; ORExI.<`W  
//if(count>4) ;k<dp7^  
// siteStop(); cM#rus?)+  
} =
XP[3~  
AC,RS7  
A8)4nOXM  
System.err.println("文件下载结束！"); =oBpS=<7  
} 7r:h_r-  
catch(Exception e){e.printStackTrace ();} 8u[_t.y4m  
} SMN.AJ J  
"aJHCi~l  
kaBjA*  
//获得文件长度 H"A%mrb  
public long getFileSize() zHJCXTM  
{ -k'<6op  
int nFileLength = -1; (80m'.X  
try{ vSgT36ZF  
URL url = new URL(siteInfoBean.getSSiteURL()); o<G 9t6~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qN!oN*  
httpConnection.setRequestProperty("User-Agent","NetFox"); GY~$<^AK  
(V{/8%mWc  
.~]|gg~  
int responseCode=httpConnection.getResponseCode(); |2
(q9j  
if(responseCode>=400) - x  
{ RZa/la*  
processErrorCode(responseCode); {;yO3];Hqw  
return -2; //-2 represent access is error t>j_C{X1(  
} ].d2CJ'  
qE
)FQeN  
z0 "DbZ;d  
String sHeader; hkMeUxS  
!]4u"e  
n Bu!2c  
for(int i=1;;i++) }3Es&p$9  
{ ({uW-%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Kd\0nf6  
//Utility.log(in.readLine()); }k^uup*{  
sHeader=httpConnection.getHeaderFieldKey(i); =ZgueUz,  
if(sHeader!=null) i)i>Ulj*i  
{ 3[m~-8  
if(sHeader.equals("Content-Length")) &[E\2 E  
{ X~{6$J|]#i  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WgNA%.|,  
break; @Z5q2Q  
} `4"8@>D  
} 8lyIL^
 
else Ot=>~(u0  
break; oF%m
  
} ^C>kmo3J  
} {R1]tGOf  
catch(IOException e){e.printStackTrace ();} |$Yk)z3  
catch(Exception e){e.printStackTrace ();} IwyA4Ak Ru  
i<uU_g'M  
5P,&VB8L  
Utility.log(nFileLength); +B?qx Q  
6
N/(cUXJ  
~
k*]Z
8Z  
return nFileLength; oo'9ZE/%  
} }x'*3z
I  
{*xE+ |  
JE.$]){  
//保存下载信息（文件指针位置） N_Us6X  
private void write_nPos() g~U
(w  
{ ETDWG_H |  
try{ kWzp*<lWe  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z-@nXt  
output.writeInt(nStartPos.length); x ;DoQx  
for(int i=0;i<nStartPos.length;i++) 2Bcc
E  
{ 6-U_TV  
// output.writeLong(nPos); +Mj6.X  
output.writeLong(fileSplitterFetch.nStartPos); %i9S"  
output.writeLong(fileSplitterFetch.nEndPos); o/AG9|()4  
} x@#>l8k?  
output.close(); /|EdpHx0  
} Nd(,oXa~  
catch(IOException e){e.printStackTrace ();} vC]X>P5Px  
catch(Exception e){e.printStackTrace ();} 6h9(u7(-N  
} H,> }t S  
J6 ~Sr  
Ez1eGPVr  
//读取保存的下载信息（文件指针位置） ,%pCcM)  
private void read_nPos() @A[)\E1  
{ C4m+Ta%  
try{ b(K"CL\p  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F^l1WX6  
int nCount = input.readInt(); Nl\`xl6y]  
nStartPos = new long[nCount]; ;4O[/;i  
nEndPos = new long[nCount]; LnR>!0:c  
for(int i=0;i<nStartPos.length;i++) Du_5iuMh  
{ V]zZb-m=  
nStartPos = input.readLong(); *Y>w0k  
nEndPos = input.readLong(); ! ._q8q\  
} rWht},-|1  
input.close(); CE"/&I  
} UyGo0POW  
catch(IOException e){e.printStackTrace ();} (cj9xROx  
catch(Exception e){e.printStackTrace ();} J|WE&5'  
} '_v~+  
KjGu !B
 
:9&c%~7B9  
private void processErrorCode(int nErrorCode) ItVN,sVJb  
{ 6A"$9sj6  
System.err.println("Error Code : " + nErrorCode); e#[Klh$]EW  
} eo+<@83  
[Uup5+MCv  
h
Q#e;1uD  
//停止文件下载 cSt)Na~C  
public void siteStop() TPp]UG  
{ /A9RmTb  
bStop = true; P<pv@l9)  
for(int i=0;i<nStartPos.length;i++) (3n "a'  
fileSplitterFetch.splitterStop(); x80IS:TP  
'5h`="  
}nrjA0WN  
} B&cIx~+  
} aUw-P{zp%  
//负责部分文件的抓取 ;21D^e  
**FileSplitterFetch.java wfo,r 7  
*/ w)dnmrKDZg  
package NetFox; MblRdj6  
@^| [J _4  
1Q@]b_"Xh  
import java.io.*; --$* q"  
import java.net.*; }`qAb/Ov  
K<P d.:  
SAP/jD$5]>  
public class FileSplitterFetch extends Thread { 6b|<$Je9  
=|oi0  
Gxw1P@<F:  
String sURL; //File URL  sS-dHa  
long nStartPos; //File Snippet Start Position 8}|et~7!  
long nEndPos; //File Snippet End Position y[m,t}gi  
int nThreadID; //Thread's ID E+]}KX:  
boolean bDownOver = false; //Downing is over 9q'&tU'a=c  
boolean bStop = false; //Stop identical (=j;rfvP  
FileAccessI fileAccessI = null; //File Access interface {SV/AN  
C hF~  
wQSan&81Q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "D'e  
{ /p !A:8  
this.sURL = sURL; Vuz.b.,i`  
this.nStartPos = nStart; /h>g-zb  
this.nEndPos = nEnd; &5 "!0  
nThreadID = id; ht
tywa^  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Yc[umn^K  
} %#2$B+  
0:V/z3?  
gGrVpOzBj  
public void run() R1zt6oY  
{ =v:?rY}  
while(nStartPos < nEndPos && !bStop) H$%MIBz>$  
{ .~i|kc]Ue  
1GY
Z1iA  
Yc7YNC.  
try{ fl-J:`zyyZ  
URL url = new URL(sURL); C5~~$7k0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;FqmZjm  
httpConnection.setRequestProperty("User-Agent","NetFox"); +[G9PP6  
String sProperty = "bytes="+nStartPos+"-"; qHk{5O3  
httpConnection.setRequestProperty("RANGE",sProperty); w~@"r#-  
Utility.log(sProperty); 2 5 \S>  
.8YxEnXw)(  
RBQ8+^  
InputStream input = httpConnection.getInputStream(); +(*HDa
|  
//logResponseHead(httpConnection); 8

W  
gKh*q.  
NsB]f{7>8+  
byte[] b = new byte[1024]; 19$A!kH\  
int nRead; /S]$Hu|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #QwkRzVoy  
{ %5e|  
nStartPos += fileAccessI.write(b,0,nRead); c!\Gj|  
//if(nThreadID == 1) *^-AOSVt,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a&'9[9E1  
} |.)LZP,  
:qE.(k1@5  
z|>TkCW6  
Utility.log("Thread " + nThreadID + " is over!"); 9'*7 (j;  
bDownOver = true; >M#@vIo?<6  
//nPos = fileAccessI.write (b,0,nRead); iM!2m$'s  
} &qbEF3p^@  
catch(Exception e){e.printStackTrace ();} |S!RQ-CF  
} f\2IKpF2  
} 4kL6aSqT  
Kg6J:HD49  
9VW/Af  
//打印回应的头信息 ,[;O'g?,g  
public void logResponseHead(HttpURLConnection con) 33~MP;  
{ >`
s"C  
for(int i=1;;i++) s&$?m[w  
{ "}71z  
String header=con.getHeaderFieldKey(i); Ll|-CY $  
if(header!=null) .?u<|4jE6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &. =8Q?  
Utility.log(header+" : "+con.getHeaderField(header)); > 'R{,1# U  
else 7n5gXiI"  
break; 9G[ DuYJI  
} |[rn/  
} _%CM<z e  
Z1,rN#p9  
nL?P/ \  
public void splitterStop() Z=&|__+d  
{ [KA^+n  
bStop = true; sTd@/>S?p  
} nVs@DH  
~|"Vl<9  
Q^ W,)%  
} %V=%ARP|  
DzR,ou  
! yJ0Am>  
/* H8YwMhE7  
**FileAccess.java DZqG7p$u4i  
*//文件访问(定位，写) Sn[xI9}O  
package NetFox; 6) i-S<(  
import java.io.*; Ovx *  
li[[AAWVm  
S})f`X9_}  
public class FileAccessI implements Serializable{ k@7#8(3  
w>
B}w  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2q[pOT'k  
RandomAccessFile oSavedFile; ;87PP7~  
long nPos; k'8q/]  
SA'
g`  
ug,AvHEnB  
public FileAccessI() throws IOException f(y+1
 
{ }-tJ.3Zw  
this("",0); >12jUm)  
} WHx#;  
vEfj3+e  
7>f2P!:  
public FileAccessI(String sName,long nPos) throws IOException ~B[e*|d  
{ _o9axBJs  
oSavedFile = new RandomAccessFile(sName,"rw"); '=;e# C`<{  
this.nPos = nPos; LZ)g&A(j?  
oSavedFile.seek(nPos); d*tWFr|J-  
} t0f7dU3e;L  
n1;a~0P  
n>)aw4  
public synchronized int write(byte[] b,int nStart,int nLen) &vmk!wAs  
{ :? )!yI  
int n = -1; waMV6w)<  
try{ i1x4$}  
oSavedFile.write(b,nStart,nLen); *w;?&)8%  
n = nLen; 6],?Y+_;)L  
} 4P#jMox  
catch(IOException e) >8/Otg+h  
{ M.Q HE2  
e.printStackTrace (); 4AL,=C3  
} g#i~^4-1  
fK:4jl-r  
(87wWhH  
return n; "iEnsP@'Wg  
} X_'tgP9  
6{;6~?U  
2K_ QZ  
} ;R6f9tu2  
m|fcWN[  
AO`@&e]o  
/* XcNL\fl1  
**SiteInfoBean.java "<|KR{/+  
*/ 1M`>;fjYa  
package NetFox; <SJ6<'  
7[=G;2<  
n`^
jNXE  
public class SiteInfoBean { ,JI]Eij^  
#8XmOJ"W3k  
!r.-7hR$  
private String sSiteURL; //Site's URL \X\< +KU  
private String sFilePath; //Saved File's Path s2L]H  
private String sFileName; //Saved File's Name 5 v.&|[\k  
private int nSplitter; //Count of Splited Downloading File s:'>G;p  
>&HW6 c  
8L:AmpQdpA  
public SiteInfoBean() mKtMI!FR  
{//nSplitter的缺省值为5 U;3t{~Ym  
//default value of nSplitter is 5 h];H]15&  
this("","","",5);  gwIR3u  
} ,62~u'hR5  
e,#w*|  
T7i>aM$+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _t,aPowX  
{ zW\a)~E  
sSiteURL= sURL; %H?B5y  
sFilePath = sPath; f'ld6jt|%  
sFileName = sName; *[cCY!+Qy  
this.nSplitter = nSpiltter; 4w|t|?  
2wO8;wiA  
Wj3i*x$  
} t$qIJt$  
PJ:!O?KVq  
j+'ua=T3  
public String getSSiteURL() O:I]v@  
{ v8)wu=u  
return sSiteURL; Ib{#dhV  
} 8Mtd}{Fw*  
hTO5*5]0zP  
m^BXLG:b  
public void setSSiteURL(String value) 5vD\?,f E  
{ sh,4n{+  
sSiteURL = value; RCa1S^.  
} e\(X:T  
kt`ln  
+uF}mZS^  
public String getSFilePath() \a0{9Xx F  
{ ir}*E=*  
return sFilePath; u0)O Fz  
} OE[7fDe'  
5X3JQ"z  
tHaHBx1P  
public void setSFilePath(String value) bkR~>F]FAu  
{ [ {"x{;  
sFilePath = value; R%LFFMVn  
} &b~X&{3,  
cb'Y
a_  
Hwd^C2v  
public String getSFileName() VO1  
{ }x$@
j  
return sFileName; dR i6
 
} xxzUey  
f }r \  
CUTj
RWQ  
public void setSFileName(String value) M'|[:I.V  
{ MZ0cZv$v!~  
sFileName = value; g#fn(A  
} 4T52vM  
)M.g<[=^  

RpU i'  
public int getNSplitter() Tn,_0  
{ p4O[X\T  
return nSplitter; VPYcA>-%u  
} [< 9%IGH  
ekfa"X_  
9pi{)PDJ  
public void setNSplitter(int nCount) _)LXD,LA  
{ j+fF$6po#t  
nSplitter = nCount; Xa-TNnws?  
} \N0wf-qa=  
} f3vl=EA4|  
b&,ZmDJh  
g~|vmVBua  
/* eo;MFd%;  
**Utility.java AD!w:jT
9  
*/ f"\klfrRI_  
package NetFox; #v$wjqK5  
TUGD!b{  
82)=#ye_P  
public class Utility { X?ZLmP7|  
;9#W#/B  
}/tf^@  
public Utility() Fw
KY;^`!d  
{ ~T9QpL1OJ  
%H_-`A`  
npytb*[|c  
} 6]GHC
yo  
"Ar|i8^G3  
//线程睡眠 j,%i.[8S  
public static void sleep(int nSecond) eMEKR5*-O  
{ ETH ($$M  
try{ 7Kj7or|  
Thread.sleep(nSecond); 7On.y*  
} `CL\-  
catch(Exception e) oFt_ yU-  
{  MkdC*|  
e.printStackTrace (); 4y4r;[@U  
} &eO.h%@  
} U0|bKU  
5&A' +]  
//日志 -ciwIS9L  
public static void log(String sMsg) ~rq:I<5  
{ S,,Wb&A$  
System.err.println(sMsg); ]f`UflMO8  
} 2h}FotlO  
VD!PF'  
QiqRx  
public static void log(int sMsg) Xrc{wDn  
{ 1Qjc*+JzO.  
System.err.println(sMsg); {~#01p5  
} JvCy&xrE;  
} %Zfh6Bl\X  
XCgC^c'  
@.dM1DN)  
/* LF(S"Of  
**TestMethod.java ]g%HU%R-m  
*/ ;?-{Uk  
package NetFox; D-m%eP.  
]r#NjP  
A~s6~  
public class TestMethod { e9C
vdR  
b$*G&d5  
~X;sa,)L1+  
public TestMethod() `"xzC $  
{ ///xx/weblogic60b2_win.exe hig t(u  
try{ J3r':I}\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);
S!iDPl~  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rdX;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +\vN#xDz  
fileFetch.start(); %2?"x*A  
} 7i=ER*F~  
catch(Exception e){e.printStackTrace ();} 1bCS4fs^>  
R^K:hKQ
 
v=IcVHuf  
} h}+Gz={Q^  
j{m{hVa  
PhmtCp0-7-  
public static void main(String[] args) b#S-u }1PE  
{ E_xk8X~  
new TestMethod(); 5YiBPB")  
} |A H@
W#7j  
} \J6e/ G  
点击下载更多相关资料