http断点续传简单实现（java)

/* z x7fRd$  
**SiteFileFetch.java (|(#W+l~  
*/ 3L;GfYr0  
package NetFox; C2~t  
import java.io.*; 6NvdFss'A{  
import java.net.*; p4ML }q8  
sz5&P )X  
> @Ux8#  
public class SiteFileFetch extends Thread { -ZmccT"8  
O{sb{kk  
n+C,v.X  
SiteInfoBean siteInfoBean = null; //文件信息Bean JZCRu_M>|  
long[] nStartPos; //开始位置 L_3undy,  
long[] nEndPos; //结束位置 Tug}P K   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 > xc7Hr~  
long nFileLength; //文件长度 T8ga)BA  
boolean bFirst = true; //是否第一次取文件 [&Kn&bdKW  
boolean bStop = false; //停止标志 (c{<JYEC  
File tmpFile; //文件下载的临时信息 rUb`_W@  
DataOutputStream output; //输出到文件的输出流 NAy3Zd}  
yK1Z&7>J>  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） ,ZVC
@P,L  
public SiteFileFetch(SiteInfoBean bean) throws IOException Nb))_+/  
{ hkSK;  
siteInfoBean = bean; }d,iA FG  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); oGK 1D  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); f}4bnu3  
if(tmpFile.exists ()) 2>E.Q@c  
{ 1:.0^?Gz  
bFirst = false; +/g/+B
_b  
read_nPos(); rPK)=[MZ  
} !y8/El  
else l?+67cQLA  
{ SA5 g~{"  
nStartPos = new long[bean.getNSplitter()]; _L?`C  
nEndPos = new long[bean.getNSplitter()]; U!GG8;4  
} O23dtH  
e}Y|'bG  
vm3B>ACJ  
%fS__Tb#u  
} /$'R!d5r
 
ebbC`eFD  
CM; r\,o  
public void run() -y8?"WB(b  
{ tgu}^TfKkg  
//获得文件长度 sqAZjfy@  
//分割文件 '.n0[2>  
//实例FileSplitterFetch Gw"H#9J} T  
//启动FileSplitterFetch线程 ,ux?wa+  
//等待子线程返回
!nQ!J+ g  
try{ 1-@[th  
if(bFirst) NJEubC?  
{ ] ~;x$Z)  
nFileLength = getFileSize(); 8 |2QJ  
if(nFileLength == -1) v&[Ff|>  
{ S7tc  
System.err.println("File Length is not known!"); R$'0<y8E*]  
} B(x$ Ln"y[  
else if(nFileLength == -2) l;4},N  
{ PD@]2lY(  
System.err.println("File is not access!"); )qGw!^8  
} 67/&AiS?  
else <&n\)R4C1  
{ ,a N8`M  
for(int i=0;i<nStartPos.length;i++) gbP]!d:I  
{ d" T">Og)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3JB?G>\!  
} D^(Nijl9U  
for(int i=0;i<nEndPos.length-1;i++) 7$ vs X  
{ gr\UI!]F  
nEndPos = nStartPos[i+1]; .OLm{  
} ar-N4+!@  
nEndPos[nEndPos.length-1] = nFileLength; %3L4&W_T  
} %P!
6cyQS  
} |hsg=LX  
OT6uAm+\7_  
efj[7K.h  
//启动子线程 }O_kbPNw  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K{eq'F5M  
for(int i=0;i<nStartPos.length;i++) 7Eo
a~  
{ +,`Cv_O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]>E)0<t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D
0'L  
nStartPos,nEndPos,i); t5r,3x!E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #0K122oY  
fileSplitterFetch.start(); oyQp"'|N  
} +R
XKI{0Km  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]a4rA+NFLB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1#KE4(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (vX+ Yw  
nEndPos = " + nFileLength); R`? '|G]P  
// fileSplitterFetch[nPos.length-1].start(); jQ &$5&o  
SE%B&8ZD  
#S?xRqkc  
//等待子线程结束 ('H[[YODh  
//int count = 0; ~j%g?;#*  
//是否结束while循环 (*{Y#XD{  
boolean breakWhile = false; {)E)&lL  
ao2NwH##  
vrr&Ve  
while(!bStop) )
bJS*#  
{ 11%<bmJ]Q3  
write_nPos(); g_<^kg"  
Utility.sleep(500); vM_UF{a$=  
breakWhile = true; LxWnPi ^  
eko$c,&jY  
-6wjc rTD  
for(int i=0;i<nStartPos.length;i++) &L&6y()G  
{ nVkPYeeT  
if(!fileSplitterFetch.bDownOver) J2rw4L  
{ 4bV&U=  
breakWhile = false; JmHEYPt0  
break; AfU~k!4`  
} :bJT2o[  
} ;?-A4!V,
 
if(breakWhile) e^;<T9Esr  
break; L9,;zkgo  
mB.yb
rig  
IM""s]  
//count++; P?- #d\qi  
//if(count>4) @FC|1=+  
// siteStop(); N3J T[7  
} ZbmBwW_ 7  
!E
e#jCXS  
*V@>E2@  
System.err.println("文件下载结束！"); _g
AU`aO^  
} " 3ryp A  
catch(Exception e){e.printStackTrace ();} uVnbOqR<X  
}  y5"b(nb  
1y\-Iz
^  
*>m,7} L  
//获得文件长度 TR@*tfS  
public long getFileSize() [^oTC;  
{ xqP DL9
\  
int nFileLength = -1; j
c%  
try{ %}T' 3  
URL url = new URL(siteInfoBean.getSSiteURL()); lB7 V4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QqpXUyHp[  
httpConnection.setRequestProperty("User-Agent","NetFox"); F]_w~1 n5  
}6U`/"RfcO  
oqLM-=0<}  
int responseCode=httpConnection.getResponseCode(); dRl*rP/  
if(responseCode>=400) Wt$" f  
{ 4z{jWNM)N  
processErrorCode(responseCode); PubO|Mf  
return -2; //-2 represent access is error lCyBdY9n  
} hUL5V1-j  
R^[b I;  
[(*ObvEF  
String sHeader; L[Z SgRTu  
<=1nr@L  
$mH'%YDIl  
for(int i=1;;i++) h-0#h/u>M  
{ w6b
\l1Z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;M)l7
f  
//Utility.log(in.readLine()); Qyh_o  
sHeader=httpConnection.getHeaderFieldKey(i); u 2)#Ml  
if(sHeader!=null) uA`EJ )d  
{ rMV<}C ^  
if(sHeader.equals("Content-Length")) 3Ryae/Nk  
{ #2dd`F8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |.asg  
break; 
o@o0V  
} 8`I/\8;H'p  
} zO@7V>2  
else nnw5 !q_  
break; pn5A6 #  
} TGSUbBgU  
} #km
ZS/"  
catch(IOException e){e.printStackTrace ();} ,WvCslZ  
catch(Exception e){e.printStackTrace ();} >~+'V.CNW  
CLQE@kF;  
kNqIPvuMr  
Utility.log(nFileLength); MLd*WpiI.  
>q+q];=(  
[xm{4Ba2X  
return nFileLength; 1Tb'f^M$  
} XGs d"UW  
ZxvqLu  
[,@gSb|D?  
//保存下载信息（文件指针位置） r~<I5MZY  
private void write_nPos() '[T#d!T  
{ JDa=+\_  
try{ |._9;T-Yde  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;*~y4'{z  
output.writeInt(nStartPos.length); KG2ij~v  
for(int i=0;i<nStartPos.length;i++) GnCO{"n  
{ ;usv/8  
// output.writeLong(nPos); LTof$4
s  
output.writeLong(fileSplitterFetch.nStartPos); +Jf45[D   
output.writeLong(fileSplitterFetch.nEndPos); Oo)MxY
PU  
} -GqMis}c  
output.close(); @i" ^b  
} t;>"V.F<1  
catch(IOException e){e.printStackTrace ();} R)[ l3  
catch(Exception e){e.printStackTrace ();} yf
lt2 R  
} bwr}Ge  
7Ud  
Qz[4M`M  
//读取保存的下载信息（文件指针位置） 9f wFSJx  
private void read_nPos() TgDx3U[  
{ -pF3q2zb  
try{ $ts%SDM  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uU|fCwQt  
int nCount = input.readInt(); Z'u:Em  
nStartPos = new long[nCount]; &efwfnG<  
nEndPos = new long[nCount]; J2vaKl  
for(int i=0;i<nStartPos.length;i++) 4ONou&T  
{ $@VQ{S  
nStartPos = input.readLong(); BGe&c,feIc  
nEndPos = input.readLong(); )`4g,W  
} Z
RD@8'1p  
input.close(); _QS+
{  
} @P$_2IU"  
catch(IOException e){e.printStackTrace ();} f^EDiG>b`  
catch(Exception e){e.printStackTrace ();} /d1 B-I  
} 65@,FDg*i  
sF+mfoMtG  
>$%rsc}^  
private void processErrorCode(int nErrorCode) >k\lE(  
{ &*w)/W  
System.err.println("Error Code : " + nErrorCode); 7yp}*b{s  
} e>GX]tK  
_&]B  
PX5K-|R  
//停止文件下载 Dej2-Y  
public void siteStop() & rsNB:!  
{ 8/tvS8I#y  
bStop = true; _NkVi_UX  
for(int i=0;i<nStartPos.length;i++) 9=-d/y?  
fileSplitterFetch.splitterStop(); 2X= pu.;F  
O<:"Irq\qr  
[|:kS  
} *j`{ K  
} @~Uu]1  
//负责部分文件的抓取 qMHI-h_A  
**FileSplitterFetch.java z. 6-D  
*/ A.D@21py  
package NetFox; e2P ds`  
H7I
&Ky  
@$e!|.{1q  
import java.io.*; szDd!(&pv  
import java.net.*; L{2KK]IF  
&~6W!w  
[q<Vm-  
public class FileSplitterFetch extends Thread { Z2%ySO  
i6.HR?n  
9"jhS0M  
String sURL; //File URL o'`:$ (  
long nStartPos; //File Snippet Start Position ipIexv1/S  
long nEndPos; //File Snippet End Position 8}Qmhm`_j=  
int nThreadID; //Thread's ID nWyn}+C-  
boolean bDownOver = false; //Downing is over ~.dmfA{  
boolean bStop = false; //Stop identical 7e`ylnP!  
FileAccessI fileAccessI = null; //File Access interface C5W} o:jE  
jMH=lQ+8  
"< c,I=A  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  UE-+P  
{ AWXBk+  
this.sURL = sURL; /c>@^  
this.nStartPos = nStart; =Eh~ wm  
this.nEndPos = nEnd; sNF[-,a  
nThreadID = id; ;(Xig$k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3fb"1z#  
} sK&[sN33  
u=U.+\f5  
|$)+h\h  
public void run() `L. kyL  
{ p
c=f,  
while(nStartPos < nEndPos && !bStop) yLDv/r  
{ @u.%z# h"1  
7a0kat'\  
Lwzk<+>w^  
try{ +im>|  
URL url = new URL(sURL); ZbZCW:8>k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zS6oz=  
httpConnection.setRequestProperty("User-Agent","NetFox"); HZ+l){u  
String sProperty = "bytes="+nStartPos+"-"; -/7[\S  
httpConnection.setRequestProperty("RANGE",sProperty); XITh_S4fs=  
Utility.log(sProperty); SGp}(j>  
 3g#  
BbV@ziL  
InputStream input = httpConnection.getInputStream(); d7*fP S  
//logResponseHead(httpConnection); qrK\f  
y\M Kd[G7  
"P@jr{zvMd  
byte[] b = new byte[1024]; x9U(,x6r  
int nRead; 9k`}fk\M  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _T{ "F  
{ IGtpL[.;/  
nStartPos += fileAccessI.write(b,0,nRead); soTmKqj E  
//if(nThreadID == 1) ^`MGlI}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f\{ynC2m  
} 3T|xUY)G4  
5g$]ou  
k^Gf2%k  
Utility.log("Thread " + nThreadID + " is over!"); RTJ\|#w  
bDownOver = true; zo^34wW^  
//nPos = fileAccessI.write (b,0,nRead); p1blPBlp  
} |@+/R .l  
catch(Exception e){e.printStackTrace ();} S]O0zv^}  
} $BPTk0Y  
} @rV|7%u  
SdJGhU  
9 :ubPqt  
//打印回应的头信息 ;4!,
19AT  
public void logResponseHead(HttpURLConnection con) |k:ecw  
{ bRhc8#kw)  
for(int i=1;;i++) He}uE0^  
{ p:/#nmC<  
String header=con.getHeaderFieldKey(i); &Oxf^x["]  
if(header!=null) 3om_Z/k  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?4^8C4  
Utility.log(header+" : "+con.getHeaderField(header)); +IM:jrT(  
else ],3#[n[ m  
break; C;EC4n+s  
} $ncJc  
} ptlcG9d-  
\D<w:\P  
a St  
public void splitterStop() ]c=nkS  
{ "3r7/>xy  
bStop = true; ?uBZ"^'  
} zBKfaQI,  
?##3E, /"9  
?c;T4@mB  
} ~hk;OB;  
E;vF :?|  
G""L1?  
/* +pefk+  
**FileAccess.java Bc!ZHW*&  
*//文件访问(定位，写) ; { MK  
package NetFox; 1>pFUf|cV  
import java.io.*; 8F;f&&L"y  
FB\lUO)U\c  
K4[XP]\jr  
public class FileAccessI implements Serializable{ ;GjZvo  
:=J^"c  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DJ
:N  
RandomAccessFile oSavedFile;  el"XD"*  
long nPos; H/I1n\  
@|i f^  
l)m]<EX  
public FileAccessI() throws IOException $OAak  
{ 0Gr^#`  
this("",0); "{lw;
AA5F  
} 3%NbT  
kYl')L6  
O5lP92],  
public FileAccessI(String sName,long nPos) throws IOException *Bj7\8cKC  
{ nB+UxU@  
oSavedFile = new RandomAccessFile(sName,"rw"); p#  4@  
this.nPos = nPos; T]fBVA  
oSavedFile.seek(nPos); I.qP$j  
} ?vd
_8C2B  
y. A]un1  
$UX^$gG  
public synchronized int write(byte[] b,int nStart,int nLen) pT;{05  
{ .vm.g=-q  
int n = -1; (0cL! N;;  
try{ bY>JLRQJ-  
oSavedFile.write(b,nStart,nLen); c@ea ;Cv  
n = nLen; pp!>:%  
} 1/l;4~p7'  
catch(IOException e) {Iu9%uR>@  
{ <8SRt-Cr  
e.printStackTrace (); KVC$o+<'`%  
} |rhCQ"H  
)=:gO`"D  
8!!iwmH{  
return n; M.(shIu!+  
} 5IsRIz[`TK  
N)&(&2  
,;)1|-^nu  
} CQ( _$  
?u)[xEx6}+  
|*5QFp  
/* "92Z"I~1  
**SiteInfoBean.java =D"H0w <zw  
*/ 6 pQbh*  
package NetFox; 2o\GU  
ENEnHu^  
pEn3:.l<  
public class SiteInfoBean { .0eHP  
cfg_xrW0^  
w{HDCPuS  
private String sSiteURL; //Site's URL NETji:d  
private String sFilePath; //Saved File's Path (K}Md~  
private String sFileName; //Saved File's Name 9tt0_*UX  
private int nSplitter; //Count of Splited Downloading File HJh9<I  
Y>N`(  
/P8`)?f~y  
public SiteInfoBean() DOzJ-uww1  
{//nSplitter的缺省值为5 q7VpKfA:M  
//default value of nSplitter is 5  Du*O|  
this("","","",5); LM~,`#3Ru  
} pH'1be{K  
G.}Ex!8R7_  
_s&sA2r<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c[DC  
{ ju@5D h  
sSiteURL= sURL; j$f`:A  
sFilePath = sPath; @uWPo2  
sFileName = sName; JuD$CHg;#  
this.nSplitter = nSpiltter; FQ72VY  
>~% _U+6  
~Xf&<&5d T  
} HxgH*IMs  
Q.dHg7+D  
n* 7mP  
public String getSSiteURL() ?pLKUAh  
{ P!Mz5QZ+  
return sSiteURL; A)X 'We  
} "E><:_,\  
t\p_QWnF  
9m:qQ1[\  
public void setSSiteURL(String value) 3}}#'5D  
{ 9kkYD  
sSiteURL = value; GsG9;6c+u  
} R^i8AbFW  
Hsoe?kUHF  
,uFdhA(i@'  
public String getSFilePath() *Y2d!9F}Sa  
{ :e&P's=
 
return sFilePath; wF`9}9q  
} abvA*|  
),K!|7#h  
P]pVYX#m  
public void setSFilePath(String value) r|bvpZV  
{ n,Z B-"dW  
sFilePath = value; <AzM~]"3  
} 9bpY>ze  
Dyx3N5?C  
ON$^_l/c  
public String getSFileName() &f\ng{  
{ L%7?
o:  
return sFileName; |VC/(A  
} b~Qd9Nf  
Tn# >"Ag  
u.}z}'-  
public void setSFileName(String value) )eFq0+6*)  
{ a*8^M\>m4  
sFileName = value; ?\7" A  
} FL5tIfV+  
Ve4!MM@
ti  
LZ@4,Uj  
public int getNSplitter() SGU~LW&  
{ pGy]t  
return nSplitter; }v[$uT-q  
} (> v1)*r  
8: KlU(J  
V0]6F  
public void setNSplitter(int nCount) y`~[R7E  
{ ((U-JeFW   
nSplitter = nCount; S> f8j?n  
} sQT0y(
FW  
} T1@]:`&  
YdgaZJs  
LWb5C{  
/* T/^ /U6JB  
**Utility.java #_tixg  
*/ 2<aBUGA  
package NetFox; pvJsSX  
)ow|n^D($M  
T/%s7!E  
public class Utility { \h%/Cp+p  
x)hp3&L  
x.7Ln9  
public Utility() Y%UfwbX!g  
{ _fH.#C  
.1yp
}&e#  
%2<G3]6^U  
} 5]WpH0kzO  
* Yr)>;^  
//线程睡眠 g`jO  
public static void sleep(int nSecond) ,$,6%"'"  
{ 29?{QJb  
try{ /x6,"M[97  
Thread.sleep(nSecond); NU*6MT4  
} <Gy)|qpK[  
catch(Exception e) 0R,?$qM\  
{
VP$`.y  
e.printStackTrace (); 'm@0[i  
} "28b&pm  
} d#N<t`  
bBkF,`/f$  
//日志 :[iWl8  
public static void log(String sMsg) `0tzQ>ZQq  
{ Uk u~"OGC  
System.err.println(sMsg); @<ba+z>"~4  
} r/E;tm[\  
s@sr.'yU  
blcd]7nK  
public static void log(int sMsg) ]7C=.'Y  
{ D>u1ngu  
System.err.println(sMsg); *dn~-W.  
} \N\Jny  
} DiyviH  
'H<0:bQ=I  
D7b<&D@  
/* \v7M`! &  
**TestMethod.java 6@-VLO))O  
*/ Kr!(<i  
package NetFox; 0xVue[ep  
P1b5=/}:V  
vMsb@@O\\  
public class TestMethod { x8Rmap@L.  
/wB<1b"  
@,D 3$P8}  
public TestMethod() )W!8,e+%  
{ ///xx/weblogic60b2_win.exe 8[SiIuIV  
try{ [kx_Izi/T  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GZ#6}/;b  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gaaW:**y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'W5r(M4U  
fileFetch.start(); 9x/HQ(1  
} ?Gc9^bB I  
catch(Exception e){e.printStackTrace ();} LlP_`fA  
s+>VqyHgf  

U+t|wK  
} Gxu&o%x[  
dUOvv/,FZT  
kAbRXID  
public static void main(String[] args) [Y_6PR  
{ A.<HOx&#  
new TestMethod(); 4oT1<n`r+  
} PW"G]G,  
} V-U,3=C  
点击下载更多相关资料