http断点续传简单实现（java)

/* DIC*{aBf  
**SiteFileFetch.java OVg&?fiP  
*/ ;%tFi  
package NetFox; odv2(\  
import java.io.*; S 'a- E![  
import java.net.*; kDmm  
R9XU7_3B  
t{md&k4  
public class SiteFileFetch extends Thread { TW|K.t@5#H  
VkQ@c;C  
[+ud7l  
SiteInfoBean siteInfoBean = null; //文件信息Bean $8tk|uh  
long[] nStartPos; //开始位置 D"7}&Ry:  
long[] nEndPos; //结束位置 oPe|Gfv\G  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )6"}M;v  
long nFileLength; //文件长度 c~ss^[qx|  
boolean bFirst = true; //是否第一次取文件  RD$:.  
boolean bStop = false; //停止标志 %OQdUH4x  
File tmpFile; //文件下载的临时信息 X9x`i  
DataOutputStream output; //输出到文件的输出流
W06aj ~7Z  
?cU,%<r  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） |]\zlH"w  
public SiteFileFetch(SiteInfoBean bean) throws IOException fY<#KM6X  
{ I)HO/i6>3  
siteInfoBean = bean; c-w #`  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5pQpzn=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); `fv5U%  
if(tmpFile.exists ()) fzsy<Vl",  
{ 9"~ FKMN  
bFirst = false;
Z#[?~P  
read_nPos(); a6{Zp{"Y  
} J8ni}\f  
else 4cjfn'x  
{ %rwvY`\  
nStartPos = new long[bean.getNSplitter()]; uwe#&V-  
nEndPos = new long[bean.getNSplitter()]; H:fKv7XL  
} I}C2;[aB  
v$ ti=uk$  
m2]N%Y  
f"6W ;b2L.  
} dGKo!;7{  
n0(Q/  
VAPeMO ck  
public void run() U]PB)  
{ !~#zd]0x;  
//获得文件长度 pH'_k k  
//分割文件 ^<I(  
//实例FileSplitterFetch >pq~ &)^u  
//启动FileSplitterFetch线程 @16GF!.  
//等待子线程返回 rN0<y4)!  
try{ sJ6.3= c  
if(bFirst) F8pA)!AH  
{ 1lw%RM  
nFileLength = getFileSize(); t"=5MaQk-  
if(nFileLength == -1) )+.=z  
{ yRXML\Ge  
System.err.println("File Length is not known!"); X%Ok ">  
} Be6Yh~m  
else if(nFileLength == -2) R1];P*>%gZ  
{ BT7{]2?&V  
System.err.println("File is not access!"); gInh+XZs  
} *EWWN?d  
else "\|P6H  
{ JP#S/kJ%3  
for(int i=0;i<nStartPos.length;i++) ,54z9F`  
{ EU[\D;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Gwd38  
} #p}GWS)  
for(int i=0;i<nEndPos.length-1;i++) O}M-6!%<,  
{ +,e#uuj$p  
nEndPos = nStartPos[i+1]; 4@9Pd &I  
} +x]/W|5  
nEndPos[nEndPos.length-1] = nFileLength; [.#nM  
} [
ZWAXl $  
} 'D\X$^
J^  
]$smF
F
 
'ZbWr*bo  
//启动子线程 *HoRYCL  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t2[/eM.G  
for(int i=0;i<nStartPos.length;i++) \VpEUU6^U  
{ gAAC>{Wh  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -S$F\%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xa`Q;J"h  
nStartPos,nEndPos,i); 7^d
r[.Q[*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tZ_'>7)  
fileSplitterFetch.start(); ale'-V)5  
} Fp\;j\pfw  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \<{a=@_k9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); __=53]jGE  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RpJ7.  
nEndPos = " + nFileLength); %"WENa/t  
// fileSplitterFetch[nPos.length-1].start(); ucN' zq  
'=dQ$fs  
h;V4|jM  
//等待子线程结束 $|K: 9  
//int count = 0; juF9:Eah  
//是否结束while循环 \.LjA_  
boolean breakWhile = false; 8t!jo.g  
^r~[3NT  
wf8{v  
while(!bStop) :>FN|fz  
{ 4=Th<,<  
write_nPos(); kL8rqv^  
Utility.sleep(500); =B}IsBn'J  
breakWhile = true; <6UXk[y  
m23"xnRB  
[qc1 V%g  
for(int i=0;i<nStartPos.length;i++) NLy4Z:&{  
{ X4%uY  
if(!fileSplitterFetch.bDownOver) ]?6wU-a  
{ 8iIp[9~=  
breakWhile = false; \U:OQ.e  
break; g5y+F
]'I  
} Z^kE]Ir#EV  
} A8-[EBkK  
if(breakWhile) 8~Kq"wrbu  
break; Ci`o;KVj  
DNGyEC  
O#)1zD}  
//count++; AjK5x@\  
//if(count>4) Ohm{m^VD"  
// siteStop(); | 6{JINW  
} Skr(C5T  
r#z
cl)rbU  
OxHcoNrz  
System.err.println("文件下载结束！"); nM[yBA  
} Bsa;,  
catch(Exception e){e.printStackTrace ();} NBk0P*SI  
} ~4fE`-O  
[Hh*lKg  
6 byeO&d  
//获得文件长度 bdL= ?KS  
public long getFileSize() 7yE\,  
{ [* <x)  
int nFileLength = -1; VeQGdyhY  
try{ \5a.JfF  
URL url = new URL(siteInfoBean.getSSiteURL()); Mt.Cj;h@^[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /43l}6I  
httpConnection.setRequestProperty("User-Agent","NetFox"); wV )\M]@  
Ph^1Ko"2  
u+8"W[ZULq  
int responseCode=httpConnection.getResponseCode(); hO"!q;<eS  
if(responseCode>=400) pS$9mzY  
{ ,C,nN
aW  
processErrorCode(responseCode); U'=8:&  
return -2; //-2 represent access is error h$8h@2%  
} 3t-STk?  
&~*](Ma  
_Q+c'q Zkl  
String sHeader; 8H7#[?F  
(\ab%M
  
Up@^C"  
for(int i=1;;i++) l8G1N[  
{ vn}m-U XA*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {0,b[  
//Utility.log(in.readLine()); 3dN`Q:1R9  
sHeader=httpConnection.getHeaderFieldKey(i); p7QZn.,=u  
if(sHeader!=null) /?;'y,(Q  
{ |%|
03}Q  
if(sHeader.equals("Content-Length")) p_I^7 $  
{ sU>IETo  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P*KIk~J  
break; ,sitOy}ks  
} o< @![P  
} UVux[qX<  
else 4EM+Ye  
break; ao)';[%9s  
} Gwk$<6E  
} /ZyMD(_J  
catch(IOException e){e.printStackTrace ();} ,IB\1#  
catch(Exception e){e.printStackTrace ();} YYpC!)  
sJLOz>  
yeiIP  
Utility.log(nFileLength); Erw1y,mF  
sFM$O232  
&|x7T<,)  
return nFileLength; 'I>USl3hI  
} PA'&]piPl:  
sSU|N;"Y  
wG49|!l6T  
//保存下载信息（文件指针位置） d.?}>jl  
private void write_nPos() #@oB2%&X?  
{ '> ib K|  
try{ y'm!h?8  
output = new DataOutputStream(new FileOutputStream(tmpFile)); t*hy"e{*a  
output.writeInt(nStartPos.length); \ ku5%y  
for(int i=0;i<nStartPos.length;i++) hJ(vD
v%  
{ Z[Tou  
// output.writeLong(nPos); h^g0|p5  
output.writeLong(fileSplitterFetch.nStartPos); j&X&&=   
output.writeLong(fileSplitterFetch.nEndPos); R=~%kt_n  
} y"yo\IDW  
output.close(); UN'n~d@~  
} eA7 Iv{M  
catch(IOException e){e.printStackTrace ();} S]fu M%  
catch(Exception e){e.printStackTrace ();} a,Pw2Gcid  
} OMK,L:poC  
JlYZ\  
@<P2di  
//读取保存的下载信息（文件指针位置） Ry
>y  
private void read_nPos() Po58@g  
{ yx Om=V  
try{ 6FzB-],  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nG<oae6z"  
int nCount = input.readInt(); ~Ykn|$_"I  
nStartPos = new long[nCount]; SOI=~BGd)  
nEndPos = new long[nCount]; ?Kgb-bXB  
for(int i=0;i<nStartPos.length;i++) bkd`7(r  
{ u@dvFzc  
nStartPos = input.readLong(); <<!fA><W  
nEndPos = input.readLong(); 'S3<' X  
} 0g[ %)C  
input.close(); +%YBa'Lk  
} /K|(O^nw  
catch(IOException e){e.printStackTrace ();} c*rH^Nz  
catch(Exception e){e.printStackTrace ();} di/QJrw  
} &jqylX  
@dv8 F "v  
?JZ$M  
private void processErrorCode(int nErrorCode) g4A{RI  
{ e@vtJaSu  
System.err.println("Error Code : " + nErrorCode); ]mMJ6n  
} 9:p-F+  
#_.JkY  
l~"T>=jq3  
//停止文件下载 SAdT#0J  
public void siteStop() jh/,G5RM9  
{ BP9#}{kE  
bStop = true; YH\9Je%jx  
for(int i=0;i<nStartPos.length;i++) ~yJ2@2I  
fileSplitterFetch.splitterStop(); qt}M&=}8Q  
(=^KP7  
"jAd.x?X7e  
} qm$(_]R~`  
} $A?9U}V#^  
//负责部分文件的抓取 n1PptR  
**FileSplitterFetch.java }sH[_%)  
*/ 3SIqod;%  
package NetFox; :V.@:x>id  
U,P>P+\@  
Ms|c"?se  
import java.io.*; Qn8xe,  
import java.net.*; l(NQk> w  
XSC=qg$  
3q
'AgiW  
public class FileSplitterFetch extends Thread { d
~~kJKK  
'$OUe {j<  
^OiL&p;r  
String sURL; //File URL fz^j3'!\  
long nStartPos; //File Snippet Start Position $Wj= V  
long nEndPos; //File Snippet End Position }T4|Kyu?  
int nThreadID; //Thread's ID /:F^*
]  
boolean bDownOver = false; //Downing is over ?Ujg.xo\  
boolean bStop = false; //Stop identical gl+d0<Rzw  
FileAccessI fileAccessI = null; //File Access interface ZjmQ  
/-p!|T}w  
K#+?oFo:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {|u"I@M*O  
{ ^i%S}VK  
this.sURL = sURL; GS>[A b+  
this.nStartPos = nStart; E<\$3G-do  
this.nEndPos = nEnd; bqED5;d'#  
nThreadID = id; KZjh<sjX|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~bZ=]i  
} ?:wb#k)Z/  
gQr+~O  
r+bGZ  
public void run() M?lh1Yu"  
{ }R}+8  
while(nStartPos < nEndPos && !bStop) #Kb /tOp1  
{ >SI'Q7k  
M,fL(b;2  
_P.I+!w:x  
try{ %C_tBNE<  
URL url = new URL(sURL); LH4A!a]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a%r!55.  
httpConnection.setRequestProperty("User-Agent","NetFox"); BI:Cm/ >  
String sProperty = "bytes="+nStartPos+"-"; ~Y x_ 3  
httpConnection.setRequestProperty("RANGE",sProperty); ,Iyc0  
Utility.log(sProperty); .j:,WF<"l5  
FPYk`D  
S-Y{Vi"2  
InputStream input = httpConnection.getInputStream(); P{9:XSa%  
//logResponseHead(httpConnection); #r9+thyC  
<(KCiM=E$  
B4b'0p  
byte[] b = new byte[1024]; ZoXz@/T  
int nRead; z&gmaYwq  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (S!UnBb&  
{ `2 <:$]  
nStartPos += fileAccessI.write(b,0,nRead); itzUq,T  
//if(nThreadID == 1) B2[f1IMI  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }i!+d,|f  
} w||t3!M+n  
OV]xo8a;  
8lV:-"+
5  
Utility.log("Thread " + nThreadID + " is over!"); t.ulG *  
bDownOver = true; NTt4sWP!I  
//nPos = fileAccessI.write (b,0,nRead); <uuumi-!%G  
} `9
r{z;UQ  
catch(Exception e){e.printStackTrace ();} Be|! S_Y P  
} 6RbDc*  
} Qbv@}[f  
9F807G\4Qt  
4fKvB@O@.  
//打印回应的头信息 9;L4\  
public void logResponseHead(HttpURLConnection con) ;3/}"yG<p  
{ ^i8,9T'=  
for(int i=1;;i++) q8$t4_pF  
{  NAD^1
0  
String header=con.getHeaderFieldKey(i); ~5HT_B U=  
if(header!=null) %<>:$4U@]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $L^%*DkM  
Utility.log(header+" : "+con.getHeaderField(header)); 5$=[x!x  
else tKt}]KHV  
break; ]00so`  
} \$_02:#  
} Ln#o:"
E  
6!]@S|vDX  
@_C]5D^J^~  
public void splitterStop() [^ }$u[  
{ ?r !kKMZ  
bStop = true; aA4RC0'  
} iAH,f5T  
[k$GUU,jY  
wG)e8,#  
}
a Y)vi$;]  
%d+Fq=<  
c \??kQH  
/* yc*cT%?g  
**FileAccess.java 9CS"s_  
*//文件访问(定位，写) TIJH}Ri  
package NetFox; $}(Z]z}O;  
import java.io.*; :Hq%y/  
1vo3aF  
(n kg  
public class FileAccessI implements Serializable{ Tg^8a,Lt  
9\Gk)0  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eI ( S)q  
RandomAccessFile oSavedFile; 2-'_Nwkl*  
long nPos; (/uN+  
H}r]j\  
h>bjG  
public FileAccessI() throws IOException 2;sTSGDG  
{ %/3+
:}@G  
this("",0); >c0leT  
} IrZjlnht  
YA,.C4=s  
Lz1KDXr`)+  
public FileAccessI(String sName,long nPos) throws IOException ,u|>
%@h  
{ gN}$$vS  
oSavedFile = new RandomAccessFile(sName,"rw"); <zqIq9}r  
this.nPos = nPos; F2zo !a8  
oSavedFile.seek(nPos); oqvu8"  
} 93n%:?l"<W  
B-LV/WJ_  
UhJS=YvT  
public synchronized int write(byte[] b,int nStart,int nLen) lai@,_<GV  
{ eM!Oc$C8[  
int n = -1; Ly(
iq  
try{ (^~a1@f,J  
oSavedFile.write(b,nStart,nLen); q2xAx1R`sV  
n = nLen; iY`[dsT  
} #q:j~4)h  
catch(IOException e) eY`z\I  
{ EJ {vJZO  
e.printStackTrace (); pImq<Z  
} U`) ";WN  
s>L-0vG  
d1#lC*.Sg  
return n; cWnEp';.  
} "d-vs t5  
z@UH[>^gj  
@wD#+Oz  
} ;LgMi5dN  
T^eD
  
yE N3/-S+  
/* I8i|tQz  
**SiteInfoBean.java V #vkj  
*/ /QS Nv  
package NetFox; 5q4wREh  
+9LzDH  
j(I(0Yyh  
public class SiteInfoBean { %J6>Vc!ix=  
EiD41N  
0<uL0FOT  
private String sSiteURL; //Site's URL J_+2]X7n  
private String sFilePath; //Saved File's Path ;ZJ. 7t'  
private String sFileName; //Saved File's Name Gmu
[UI}w8  
private int nSplitter; //Count of Splited Downloading File ,^CG\);  
?ZTA3mV?+  
N\ <riS9  
public SiteInfoBean() }qGd*k0F0  
{//nSplitter的缺省值为5 wy|b Hkr_  
//default value of nSplitter is 5 i*l=xW;bM  
this("","","",5); xX%{i0E  
} IRLAsb3  
]hlQU%&  
xTG5VBv  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S9*68l  
{ KD\%B5Jy  
sSiteURL= sURL; D|Tz{DRG  
sFilePath = sPath; Bs3&yEq(  
sFileName = sName; on hLhrZ  
this.nSplitter = nSpiltter; mb_6f:Qh3  
DIYR8l}x  
"&qAV'U
 
} w[vccARQ  
k0FAI0~(  
E}zGY2Xx  
public String getSSiteURL() I7h v'3u  
{ b$Ei>%'/";  
return sSiteURL; y:zNf?6&  
} B!x6N"  
BQ,749^S  
 f^}n#  
public void setSSiteURL(String value) 4<<eqxI$|  
{ Wf?[GO  
sSiteURL = value; ?W dY{;&  
} KWYjN h#*  
3it*l-i\  
,y0 &E8Z  
public String getSFilePath() kxrYA|x  
{ SPe%9J+  
return sFilePath; cAx$W6
S  
} ,ZYPffu<*  
}]1C=~lC  
wKcuIc$  
public void setSFilePath(String value) {Gh9(0,B?  
{ CE (zt  
sFilePath = value; $<VH~Q<  
} f\hQ>MLzt  
#xR=U"  
> B;YYj~f}  
public String getSFileName() lwG)&qyVd  
{ rw 2i_,.*~  
return sFileName; B}zBbB  
} ;*Mr(#R  
.i;?8?  
DgRn^gL{Q  
public void setSFileName(String value) a&kt!%p:  
{ @}r s6 G  
sFileName = value; Nw,|4S  
} <}xgp[O  
qs8^qn0A  
^\S~rW.3_  
public int getNSplitter() H7drDw  
{ \,m*CYs`  
return nSplitter; hZ|0<u  
} +s7w@  
jMX+uYx M  
',D%,N}J  
public void setNSplitter(int nCount) h*hkl#  
{ h`vT[u~l  
nSplitter = nCount; (bpxj3@R  
} 19[.&-u"  
} JS?%zj&@  
C!1)3w|  
5|}u25J  
/* +~==qLsU  
**Utility.java O#{`Fj`  
*/ GAs.?JHd  
package NetFox; svt3gkR0  
[tC=P&<  
2h@&yW2j  
public class Utility { ww+,GnV  
iTT7<x  
x*X{*?5@  
public Utility() H4wDF:n0H  
{ SpIiMu(  
|g!$TUS.  
FLG{1dS  
} 0=9$k   
q&:%/?)x  
//线程睡眠 McbbEs=)  
public static void sleep(int nSecond) [1Qg
*   
{ WFmW[< g  
try{ 3:c6x kaw  
Thread.sleep(nSecond); cUw$F{|W  
} )RWY("SUy1  
catch(Exception e) ?oV|.LM:W  
{ &tiJ=;R1  
e.printStackTrace (); &-
My[t  
} [s] ZT  
} A^|~>9  
!
X[7m  
//日志 b`GKGqbJ  
public static void log(String sMsg) k O.iJcZg  
{ f"4w@X2F  
System.err.println(sMsg); m3(p7Z^Bq  
} NE &{_i!  
#7YJ87<E  
gTLBR  
public static void log(int sMsg) o>]z~^c  
{ u{sb^cmy  
System.err.println(sMsg); 8RVRfy,w  
} #B!M,TWf9s  
} k2#|^N  
wT,=C'  
va"bw!zXo*  
/* 9@nd>B  
**TestMethod.java Vhe$vH  
*/ u3Zu ~C  
package NetFox; X<v1ES$  
_1YC9}  
=?\%E[j  
public class TestMethod { ^oE#;aS  
u2[L^]|  
d+ [2Sm(7  
public TestMethod() X]W(  
{ ///xx/weblogic60b2_win.exe uA t{WDHm  
try{ _ib @<%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AW!A+?F6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iG=Di)O  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }{&;\^i  
fileFetch.start(); CHCT e  
} [;~"ctf{  
catch(Exception e){e.printStackTrace ();} nuA 0%K  
F]0 qt$GO  
j0{Qy;wP )  
} >V\^oh)t]t  
]9W7]$  
5e?<x>e  
public static void main(String[] args) tCwB7c-  
{ 7y.iXe!P  
new TestMethod(); ao
|n<*}  
} e3[Q6d&|  
} `z7,HJ.0c  
点击下载更多相关资料