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http断点续传简单实现(java)

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/* #}A"yo  
**SiteFileFetch.java u`ir(JIj]  
*/ $z=a+t *  
package NetFox; ~d*Q{v~3  
import java.io.*; rwWOhD)RU  
import java.net.*; :Drf]D(sMX  
P~7(x7/7~  
lMv6QL\>'  
public class SiteFileFetch extends Thread { \VPw3  
"8QRYV~Z  
=!Ik5LiD  
SiteInfoBean siteInfoBean = null; //文件信息Bean {i>AQ+z61f  
long[] nStartPos; //开始位置 !@C-|=9G  
long[] nEndPos; //结束位置 MN: {,#d0  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 'o='Q)Dk  
long nFileLength; //文件长度 /_{-~0Z=@B  
boolean bFirst = true; //是否第一次取文件 w1Bkz\95  
boolean bStop = false; //停止标志 PKlR_#EB?  
File tmpFile; //文件下载的临时信息 .ATpwFal  
DataOutputStream output; //输出到文件的输出流 >~g-  
%! ` %21  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?e%*q^~Cu  
public SiteFileFetch(SiteInfoBean bean) throws IOException )U/Kz1U  
{ = MByD&o`  
siteInfoBean = bean; 5;`Ot2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); O>E}Lu;|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {-)^?Zb @  
if(tmpFile.exists ()) R0t!y3r&N  
{ ,e'r 0  
bFirst = false; FQek+[ox  
read_nPos(); uc9h}QJ*  
} <?41-p-;  
else +G;<D@gSa0  
{ h-p}Qil,  
nStartPos = new long[bean.getNSplitter()]; le:}M M  
nEndPos = new long[bean.getNSplitter()]; R3g)LnN  
} gmp@ TY=:L  
@tT`s^e  
ru:"c^W:[  
G[}v?RLI  
} u<j;+-]8h  
8P ]nO+  
^*jwe^  
public void run() .1(_7!m@  
{ kTjn%Sn,  
//获得文件长度 bAlty}U  
//分割文件 HOi~eX1d  
//实例FileSplitterFetch k;qS1[a  
//启动FileSplitterFetch线程 CG uuadNI  
//等待子线程返回 ll__A|JQ  
try{ B9l~Y/3|  
if(bFirst) -axKnfj  
{ CUDA<Fm  
nFileLength = getFileSize(); q:_:E*o  
if(nFileLength == -1) A}"|_ &E  
{ we}xGb.u  
System.err.println("File Length is not known!"); dPO"8HQ  
} CLND[gc  
else if(nFileLength == -2) #-%D(=&I  
{ M|nLD+d~8  
System.err.println("File is not access!"); E2|M#Y  
} ;$tdn?|  
else qFVZhBC  
{ j6s j2D  
for(int i=0;i<nStartPos.length;i++) 1<:5b%^c  
{ &wQ<sVQ0$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); V 2Xv)  
} Zl[EpXlZ  
for(int i=0;i<nEndPos.length-1;i++) f0eQq;D$K  
{ PE.UNo>o  
nEndPos = nStartPos[i+1]; tOXyle~C  
} Ew4D'; &;  
nEndPos[nEndPos.length-1] = nFileLength; 9z?c0W5x  
} e"1mdw"  
} UhR^Y{W5  
wsdZwik  
sudh=_+>  
//启动子线程 &$ }6:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eP (*.  
for(int i=0;i<nStartPos.length;i++) q AVypP?J  
{ 8K^#$,.."  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xlcCL?qQj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -qpvVLR,  
nStartPos,nEndPos,i); ;0Ua t  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N[9o6Nl|a  
fileSplitterFetch.start(); Ri"rT] '  
} j7d^g a-`  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xJ#O|7N  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xTk6q*NvT^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]G&[P8hz B  
nEndPos = " + nFileLength); 'h ?  
// fileSplitterFetch[nPos.length-1].start(); b+Sj\3fX  
ql%K+4@  
i=5!taxu}E  
//等待子线程结束 eG+$~\%Fub  
//int count = 0; O-0 5.  
//是否结束while循环 S#CaJ}M  
boolean breakWhile = false; ^?|4<Rm  
BgN^].z&  
t(<k4ji,  
while(!bStop) /?BTET  
{ LQqba4$  
write_nPos();  irh Z  
Utility.sleep(500); 2K3j3|T  
breakWhile = true; nUs=PD3)  
6x5Q*^w  
m5/]+xdNX  
for(int i=0;i<nStartPos.length;i++) [4EIy"  
{ f7zB_hVDmE  
if(!fileSplitterFetch.bDownOver) V(XU^}b#  
{ g[y&GCKY!=  
breakWhile = false; Ce//; Op  
break; Nnn~7  
} ,nog6\  
} bs}SFTL  
if(breakWhile) Rhlm  
break; U4Zx1ieCKH  
HI1|~hOb'  
MF$Dx| Tcj  
//count++; 'oGMr=gp<&  
//if(count>4) EWl9rF@I  
// siteStop(); ">B&dNrt  
} |+~P; fG  
O*2{V]Y @  
i Ya)*,  
System.err.println("文件下载结束!"); Lcg1X3$G  
}  w@mCQ$  
catch(Exception e){e.printStackTrace ();} F" G+/c/L  
} BGNZE{K4"  
!9qw  
o8g] ho  
//获得文件长度 ]}S9KP  
public long getFileSize() "1dpv \  
{ &~<i" W  
int nFileLength = -1; +pUYFDwFx  
try{ ^tyqc8&  
URL url = new URL(siteInfoBean.getSSiteURL()); H[R6 ?H@$F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dtQ3iuV %  
httpConnection.setRequestProperty("User-Agent","NetFox"); mE+=H]`.p  
PMiu "  
?mi}S${g  
int responseCode=httpConnection.getResponseCode(); $v8T%'p+  
if(responseCode>=400) 3]NKAPY  
{ ]Gj%-5G  
processErrorCode(responseCode); b;`MHEzw&q  
return -2; //-2 represent access is error }WR@%)7ay  
} NUBzc'qb  
1@-l@ P  
?iaO+G&|  
String sHeader; rIyIZWkI  
t[({KbIy  
0p,_?3nX  
for(int i=1;;i++) Nog{w  
{ JBV 06T_4o  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G]-\$>5R  
//Utility.log(in.readLine()); # b3 14  
sHeader=httpConnection.getHeaderFieldKey(i); ieOw&  
if(sHeader!=null) fX LsLh+~D  
{ aTaL|&(  
if(sHeader.equals("Content-Length")) }PMlG  
{ IQ JFL +f  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GB*^?Ii  
break; kT^`j^Jr  
} qP/McH?  
} AAi4} 8+\  
else %@I= $8j  
break; b^~4k; <  
} p%Ns f[1>  
} wLq#,X>%B  
catch(IOException e){e.printStackTrace ();} >'3nsR  
catch(Exception e){e.printStackTrace ();} [MAvU?;  
vA?3kfL|#  
}y|_v^  
Utility.log(nFileLength); O/l/$pe  
h?QGJ^#8  
#E/|W T  
return nFileLength; +D h?MQt?  
} =4/K#cQ  
Z4k'c+  
9:!V":8q  
//保存下载信息(文件指针位置) >(gbUW  
private void write_nPos() %zjyZ{=  
{ t4zKI~cO  
try{ PTF|"^k+   
output = new DataOutputStream(new FileOutputStream(tmpFile)); {o %OG/!1  
output.writeInt(nStartPos.length); R|\kk?,u  
for(int i=0;i<nStartPos.length;i++) OQ3IkE`G  
{ b\SB  
// output.writeLong(nPos); oPxh+|0?  
output.writeLong(fileSplitterFetch.nStartPos); I_`$$-|  
output.writeLong(fileSplitterFetch.nEndPos); 2N&S__  
} )uCa]IR  
output.close(); / 7 R0w  
} 9 b&HqkXX  
catch(IOException e){e.printStackTrace ();} W 6R/{H  
catch(Exception e){e.printStackTrace ();} VkC1\L6  
} ;3 =RM\  
A2nL=9~   
FdxV#.BE  
//读取保存的下载信息(文件指针位置) bL%-9BG  
private void read_nPos() "6WE6zq   
{ &7w*=f8I  
try{ r#mH[|@W~  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G'iE`4`2  
int nCount = input.readInt(); #!j wn^yq  
nStartPos = new long[nCount]; a/~1CrYr  
nEndPos = new long[nCount]; _o6Zj1p  
for(int i=0;i<nStartPos.length;i++) ib(4Y%U6~  
{ aslb^  
nStartPos = input.readLong(); ~kZ? e1H  
nEndPos = input.readLong(); a^)@ }4  
} Vpxsg CS  
input.close(); c*V/2" 5  
} Q/l388'  
catch(IOException e){e.printStackTrace ();} 239g pf]}  
catch(Exception e){e.printStackTrace ();} d?[8VfAnh  
} )%I62<N,z  
1[(/{CClB  
\2 [  
private void processErrorCode(int nErrorCode) _WBWFGj  
{ 0w".o!2\U{  
System.err.println("Error Code : " + nErrorCode); h(FFG%H(  
} Z"9D1Uk  
j-/F *P  
YZc{\~d  
//停止文件下载 ^B'N\[  
public void siteStop() $btk48a7  
{ ^Zq3K  
bStop = true; LHusy;<E[  
for(int i=0;i<nStartPos.length;i++) U1pwk[  
fileSplitterFetch.splitterStop(); Wl{}>F`W[  
sWMY Lo  
: UDh{GQ*  
} _3m\r*(vmQ  
} 'q{d? K  
//负责部分文件的抓取 _^NL{R/  
**FileSplitterFetch.java `6Yk-5  
*/ q[~+Zm  
package NetFox; 8sU}[HH*1  
TxmKmZ u  
RxGZ#!j/  
import java.io.*; P?M WT]fY  
import java.net.*; Hg+bmwM  
7HQ|3rt  
10..<v7  
public class FileSplitterFetch extends Thread { R5r CCp  
kO' NT:  
=BgQ Ss/^c  
String sURL; //File URL  tZN'OoZ  
long nStartPos; //File Snippet Start Position Wo/LrCg  
long nEndPos; //File Snippet End Position a q]bF%7  
int nThreadID; //Thread's ID ,M9Hdm  
boolean bDownOver = false; //Downing is over Y'x+! &H  
boolean bStop = false; //Stop identical g:[yA{Eh  
FileAccessI fileAccessI = null; //File Access interface T3/Gl 6f  
0 t0m?rVW  
8'VcaU7Nh  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a>)|SfsE  
{ /~_,p,:aP  
this.sURL = sURL; `j(-y`fo  
this.nStartPos = nStart; uVLKR PY  
this.nEndPos = nEnd; 6cTd SE  
nThreadID = id; Eh.NJI(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @l@erCw@  
} %g=SkQ&d  
F44KbUH  
u\}"l2 r  
public void run() Xs$UpQo  
{ 0)9'x)l:  
while(nStartPos < nEndPos && !bStop) ]t.6bb4  
{ 8i?:aN[.1b  
Aw7_diK^  
u*<knZ~ty  
try{ J+f*D+x1  
URL url = new URL(sURL); 7\Wq:<JL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )\l(h%s[I  
httpConnection.setRequestProperty("User-Agent","NetFox"); -i"?2gK  
String sProperty = "bytes="+nStartPos+"-"; ,&rHBNS  
httpConnection.setRequestProperty("RANGE",sProperty); rL<a^/b/=  
Utility.log(sProperty); bjB4  
:eW`El  
.#}`r`/  
InputStream input = httpConnection.getInputStream(); S2"H E`  
//logResponseHead(httpConnection); vUgMfy&  
yq\p%z$:  
|eFce/  
byte[] b = new byte[1024]; 0I"r*;9?K  
int nRead; |Fp+9U  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4xzoA'Mb@  
{ oC1Nfc+  
nStartPos += fileAccessI.write(b,0,nRead); ~Jx0#+z9V  
//if(nThreadID == 1) P^& =L&U  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eh|v>Yew  
} #@K %Mx  
9 az{j 1  
0m&W: c  
Utility.log("Thread " + nThreadID + " is over!"); {K>}eO:K  
bDownOver = true; ]Qh0+!SdG  
//nPos = fileAccessI.write (b,0,nRead); NmZowh$M  
} \LQ54^eB  
catch(Exception e){e.printStackTrace ();} Q*8=^[x  
} NaYr$`  
} +|TFxaVz  
RP~ hi%A  
Eh/Z4pzT  
//打印回应的头信息 eaCh;IpIf  
public void logResponseHead(HttpURLConnection con) !5=S 2<UX  
{ }J|Pd3Q Sf  
for(int i=1;;i++) I&|J +B?#  
{ 8;1,saA_9  
String header=con.getHeaderFieldKey(i); !t!\b9=  
if(header!=null) b[`fQv$G  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2mfKy9QxO  
Utility.log(header+" : "+con.getHeaderField(header)); O}mz@- Z  
else 7':qx}c#!1  
break; db5@+_  
} pF}WMt  
} zJX _EO  
db0]D\  
KkD&|&!Q7u  
public void splitterStop() VJ()sbl{k  
{ K%RjWX=H  
bStop = true; NX9K%J  
} *_CzCl^   
~Rk ~Zn  
yZw5?{g@  
} ?'+ kZ|  
'fr~1pmx#3  
t p<wMrq<  
/*  mPS27z(  
**FileAccess.java & ( i_s  
*//文件访问(定位,写) .<kbYo:MV  
package NetFox; P QA}_o  
import java.io.*; 6PdLJ#LS  
xfADks2w  
qpXsQim$~  
public class FileAccessI implements Serializable{ R.$1aqA}  
8(|lP58~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JJVdq-k+`  
RandomAccessFile oSavedFile; PiZU _~A  
long nPos; r`5svY  
I*hzlE  
r%UsUj  
public FileAccessI() throws IOException IT=<p60"  
{ mVNHH!  
this("",0); 8\B]!  
} Gx/kel[Y}  
@z1pE@7jK  
kYnp$8  
public FileAccessI(String sName,long nPos) throws IOException $ v0beN6MG  
{ HGl.dO 7NU  
oSavedFile = new RandomAccessFile(sName,"rw"); =@y ?Np^A  
this.nPos = nPos; >N8*O3  
oSavedFile.seek(nPos); \zx$]|AQ  
} m*H' Cb  
?:+sjHzXT  
\<0xg[  
public synchronized int write(byte[] b,int nStart,int nLen) c01i !XS  
{ G7uYkJO  
int n = -1; ;?.w!|6  
try{ 32x[6"T  
oSavedFile.write(b,nStart,nLen); hG8<@  
n = nLen; lNba[;_  
} bK#SxV  
catch(IOException e) GW\66$|  
{ J`xCd/G  
e.printStackTrace (); w~wg[d  
} "'v^X!"  
T3,}CK#O   
L. DD  
return n; +\)a p  
} cT(=pMt8>  
KuJNKuHa.  
:jr`}Z%;y  
} +Hk r\  
GvI8W)d3,R  
P B?92py&  
/* s|\\"3  
**SiteInfoBean.java fOJTy0jX8  
*/ v$~$_K  
package NetFox; eI3ZV^_Ps  
gnN"6r1  
 rBUWzpE"  
public class SiteInfoBean { z=yE- I{  
O 8XHaVLg3  
*~0U4kw+  
private String sSiteURL; //Site's URL 7Xf52\7n  
private String sFilePath; //Saved File's Path K n,td:(  
private String sFileName; //Saved File's Name b!oj3|9  
private int nSplitter; //Count of Splited Downloading File 9|NH5A"H.  
?4cj"i  
\qz! v  
public SiteInfoBean() |qz&d=>  
{//nSplitter的缺省值为5 {@ Z=b 5/P  
//default value of nSplitter is 5 oe<DP7e  
this("","","",5); a4\j.(w)$D  
} X+kgx!u'y  
2Og<e|  
,#U[)}im  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W^YaC (I  
{ RmRPR<vGW  
sSiteURL= sURL; $0XR<D  
sFilePath = sPath; wDDNB1_ E  
sFileName = sName; NOFuX9/'w  
this.nSplitter = nSpiltter; #7['M;_  
`!Yd$=*c_&  
=z[$ o9  
} eI,H  
2{<o1x,Ym  
\![ p-mW{  
public String getSSiteURL() l 1vI  
{ DR7JEE  
return sSiteURL; ?azcWf z0  
} 3 #"!Hg  
>!Dp'6  
q~`dxq`}  
public void setSSiteURL(String value) <b:xyHS  
{ bs0[ a 1/  
sSiteURL = value; @Yn+ir0>O  
} V5'(op/  
mgMa)yc!dp  
otX/sg.B*  
public String getSFilePath() jss.j~8  
{ xVk5%  
return sFilePath; Ey=ymf.}  
} qe 'RvBz  
3~1Gts  
Y_)xytJ$  
public void setSFilePath(String value) +U)4V}S)  
{ M+*K-zt0  
sFilePath = value; 1my1m  
} 8SA" bH:  
+o?;7  
n8tw8o%&[  
public String getSFileName() 9yz@hdG  
{ %n 6NVi_[  
return sFileName; /@B2-.w  
} C5g9Gg  
! (Q[[M  
$0k7W?tu  
public void setSFileName(String value) \q\"=  
{ +)LCYDRV7  
sFileName = value; 0O[le*3b  
} YSrjg|k*  
&\%\"Zh  
""A6n{4  
public int getNSplitter() %JgdLnQE  
{ \)?+6D'#  
return nSplitter; )-0+O=v  
} /_qHF-  
3N 5@<:2`  
P=PeWX*L<Z  
public void setNSplitter(int nCount) v*OV\h.  
{ !_FTy^@c2  
nSplitter = nCount; nxB[T o*P  
} zz!jt A  
} *d`KD64  
bp<,Xfl  
zhJ0to[%?  
/* 5|cRHM#  
**Utility.java 'E&tEbY  
*/  AGm=0Om  
package NetFox; *?\u5O(  
N<ux4tz  
,}O33BwJp  
public class Utility { C`R<55x6  
iL2__TO  
A{e>7Z72  
public Utility() w3z'ZCcr;"  
{ ':3[?d1Es  
G<* Iw>ep  
C1+f\A|9FP  
} .9N7`  
>bd@2au9!  
//线程睡眠 ~sZ$`t  
public static void sleep(int nSecond) y+Hz(}4  
{ D(OJr5Gg  
try{ 1$+8wDVwad  
Thread.sleep(nSecond); @+l=R|  
} }LeS3\+UHl  
catch(Exception e) :t<S  
{ Bgn%d4W;G  
e.printStackTrace (); vw4b@v-XQ3  
} _-3n'i8  
} 4$WR8  
?O3d Sxi  
//日志 <nb%$2r1  
public static void log(String sMsg) K8Q3~bMf  
{ P@f#DX )  
System.err.println(sMsg); k'k}/Hxub  
} C fM[<w   
K yyVO"  
_9JFlBx  
public static void log(int sMsg) U1HG{u,"y  
{ D6H?*4f]  
System.err.println(sMsg); $8xb|S[  
} p_(En4QSH  
} rlGv6)vb  
gO)":!_n W  
)$1>6C\  
/* T2/:C7zL  
**TestMethod.java !n` |k  
*/ 22=sh;y+2  
package NetFox; *c [^/  
J8i,[,KcE  
~\8(+qIv%f  
public class TestMethod { d,?Tq  
d#]hqy  
:vX%0|  
public TestMethod() #\ `kg#&  
{ ///xx/weblogic60b2_win.exe ZX64kk+  
try{ fIl!{pv[  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jw9v&/-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _Z!@#y@j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8#V D u(  
fileFetch.start(); 2aX*|DGpw  
} ~ !!\#IX  
catch(Exception e){e.printStackTrace ();} dJ m9''T')  
fBctG~CJH  
b,YNCb]H  
} 0#Lmajs  
aZCq{7Xs  
R"9w VM;*c  
public static void main(String[] args) XL^05  
{ D%nd7 |  
new TestMethod(); gFKJbjT|  
} PkI+z_  
} v&'#Gg  
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