http断点续传简单实现（java)

/* {0;3W7  
**SiteFileFetch.java N?5x9duK  
*/ =7m}yDs6$  
package NetFox; l3Lyea:  
import java.io.*; S a4W`  
import java.net.*; kN%MP6?J  
&AlJ "N|  
?7M.o  
public class SiteFileFetch extends Thread { 52.>+GC  
S.Z9$k%  
M[z)6.  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3Wwj p  
long[] nStartPos; //开始位置 UG'bOF4  
long[] nEndPos; //结束位置 Wm H~m k"  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 F q!fWl  
long nFileLength; //文件长度 <\0vR20/  
boolean bFirst = true; //是否第一次取文件 TZtjbD>B  
boolean bStop = false; //停止标志 >7roe []-|  
File tmpFile; //文件下载的临时信息 e5.h ?  
DataOutputStream output; //输出到文件的输出流 <,AS8^$X[  
_DrJVC~6@  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） =l.+,|ZH!  
public SiteFileFetch(SiteInfoBean bean) throws IOException [HN|\afz  
{ *26334B.R  
siteInfoBean = bean; ]uspx[UIc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); R
Jy=pNztm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ]r3Kg12
Mi  
if(tmpFile.exists ()) S}f?.7  
{ =C
L} $_  
bFirst = false; 1yV: qp  
read_nPos(); 4O:W#bx  
} <$N"q  
else u
Nn[[LS  
{ J*l4|^i<  
nStartPos = new long[bean.getNSplitter()]; oQv3GpO  
nEndPos = new long[bean.getNSplitter()]; \}~s2Y5j  
} Y-'78BJk  
0<PR+Iv*i  
}<z_Q_b+e  
q %0Cg=  
} hky;CD~$  
O$kq`'9  
peJKNX.!q  
public void run() |7B!^ K  
{ c*`>9mv  
//获得文件长度 goJ|oi  
//分割文件 =?h~.lo  
//实例FileSplitterFetch 7 Sa1;%R  
//启动FileSplitterFetch线程 66#
"  
//等待子线程返回 7~ztwL  
try{ __[xD\ES  
if(bFirst) PyA&ZkX>  
{ ^1Xt]T`e  
nFileLength = getFileSize(); m=Q[\.Ra  
if(nFileLength == -1) <*t4D-os  
{ U!XS;a)
 
System.err.println("File Length is not known!"); kD) $2I?  
} }pa9%BQI  
else if(nFileLength == -2) 4d_s%n?C  
{ l;sy0S"DO]  
System.err.println("File is not access!"); Bm\qxQ  
} _5MNMVLwW  
else QRLJ_W^&u  
{ )RYG%  
for(int i=0;i<nStartPos.length;i++) M(d6Z2ibh  
{ (~)%Fo9X"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); DMF -Y-h  
} mR8W]'gl.L  
for(int i=0;i<nEndPos.length-1;i++) z4@k$ L8  
{ 9'x)M?{8  
nEndPos = nStartPos[i+1]; q!f1~aG  
} s4%(>Q  
nEndPos[nEndPos.length-1] = nFileLength; rdnRBFt  
} Xnuzr"4u  
} /U6%%%-D`  
\<vNVz7.D  
fbFX4?-  
//启动子线程 Qp2I[Ioz3  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9_fePS|Z4  
for(int i=0;i<nStartPos.length;i++) fWF|,A>>b  
{ ^). )  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D;Gq)]O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OzT#1T1'c  
nStartPos,nEndPos,i); Dml*T(WM>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !:LJzROh  
fileSplitterFetch.start(); 4yaxl\2  
} T\VNqs@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x90jw$\%7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *?yJkJ"  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1!p/6  
nEndPos = " + nFileLength); yMLOUUWa8x  
// fileSplitterFetch[nPos.length-1].start(); >QHo@Zqj(  
Gg\G'QU  
Aa?I8sbc  
//等待子线程结束 u@p?  
//int count = 0; )'Wb&A'  
//是否结束while循环 M}DH5
H"s  
boolean breakWhile = false; @c'|Iqy`  
.bf<<+'o  
9kKnAf4Z  
while(!bStop) D\^WXY5e%y  
{ xjdw'v+qZo  
write_nPos(); G6K  <  
Utility.sleep(500); JNWg|Qt  
breakWhile = true; K?#]("De6  
,pK|SL  
NHw x:-RH  
for(int i=0;i<nStartPos.length;i++) gM>=%/.  
{ 4z:#I;  
if(!fileSplitterFetch.bDownOver) `ya;:$(6  
{ 6@tvRDeaDW  
breakWhile = false; ]WJfgN4  
break; IfDx@?OB  
} 4c~>ci,N?(  
} Bn]K+h
\E  
if(breakWhile) Uz%Z&K  
break; J N
C  
n,P5o_^:  
iy\KzoB  
//count++; 17hT
r  
//if(count>4) \g-
j9|0  
// siteStop(); ,`td@Y  
} g"Qh]:  
5;)*T6Y  
BbJkdt7  
System.err.println("文件下载结束！"); v| z08\a[  
} ^T4Ay=~{  
catch(Exception e){e.printStackTrace ();} 2 Tvvq(?T  
} h5|.Et  
+rNkN:/L  
TrE3S'EU#R  
//获得文件长度 YpdNX.P,  
public long getFileSize() <XQ.A3SG!  
{ HTz+K6&  
int nFileLength = -1; c\cZ]RZ  
try{ MM{_Ur7Q  
URL url = new URL(siteInfoBean.getSSiteURL()); ]*%+H|l  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f?Bj _z  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1 [z'G)v  
K2'O]#  
Jd 3@cLCe-  
int responseCode=httpConnection.getResponseCode(); 3+OsjZ  
if(responseCode>=400) V7=SV:+1or  
{ kpfwqHT  
processErrorCode(responseCode); oB c@]T5>  
return -2; //-2 represent access is error e[X
q  
} m.%`4L^`T  
Aq#/2t  
lx,`hl%  
String sHeader; F=@i6ERi  
#Gv{UU$]  
d<o.o?Vc  
for(int i=1;;i++) wpPn}[a  
{ `T!#@&+  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'bW5Fr>W  
//Utility.log(in.readLine()); ]]iO- }  
sHeader=httpConnection.getHeaderFieldKey(i); v:ER4  
if(sHeader!=null) 96|[}:+$&:  
{ >cOeiK  
if(sHeader.equals("Content-Length")) 0x)dnq\  
{ j033%p+Xc  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p{;i& HNdp  
break;   &LQ%  
} t Y1Et0  
} &m{'nRU}c  
else 8KjRCm,I  
break; Z/ bB h  
} utO.WfWP  
} V+B71\x<  
catch(IOException e){e.printStackTrace ();} KI&:9j+M)  
catch(Exception e){e.printStackTrace ();} *FgJ|y6gk  
>w'$1tc?+F  
%l9$a`&  
Utility.log(nFileLength); HD# r0)  
R"6;NPeo  
2z2`  
return nFileLength; |w)5;uQ&\  
} J=WB6zi  
setLdEi  
o$_93<zc  
//保存下载信息（文件指针位置） IS_Su;w>4  
private void write_nPos() $Tl<V/  
{ k khE}qSD  
try{ iQ`]ms+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); DvT+`X?R  
output.writeInt(nStartPos.length); /
8CY0Ey  
for(int i=0;i<nStartPos.length;i++) *{/@uO  
{ F&@|M(  
// output.writeLong(nPos); ]A:(L9  
output.writeLong(fileSplitterFetch.nStartPos); K84
&sSi  
output.writeLong(fileSplitterFetch.nEndPos); m/${8  
} 6}&^=^-  
output.close(); i2F(GH?p[  
} aw$Y`6,S  
catch(IOException e){e.printStackTrace ();} xks?y.wA  
catch(Exception e){e.printStackTrace ();} zNtq"T[  
} Lx+`<<_dJ  
12gw#J/)9h  
W,NL*($^  
//读取保存的下载信息（文件指针位置） E/O5e(h  
private void read_nPos() E 5kF^P  
{ @FX{M..  
try{ %!W%#U0  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X8 qIia  
int nCount = input.readInt(); T_ ^C#>  
nStartPos = new long[nCount]; 6v47 QW|'  
nEndPos = new long[nCount]; #8?^C]*{0  
for(int i=0;i<nStartPos.length;i++) 3V-6)V{KaE  
{ %8D?$v"#Z  
nStartPos = input.readLong(); :('I)C  
nEndPos = input.readLong(); :W
X0,-Gn  
} w~-X>~
}  
input.close(); {8m1dEC^@Q  
} @36S}5Oa  
catch(IOException e){e.printStackTrace ();} zD_HyGf  
catch(Exception e){e.printStackTrace ();} >h7$v~nra  
} +qE']yzm!  
"L_-}B
K  
hWxT!  
private void processErrorCode(int nErrorCode) #: hVF/  
{ YN^jm  
System.err.println("Error Code : " + nErrorCode); TcZN%  
} 9.-47|-9C  
b`]M|C [5  
!aeNq82  
//停止文件下载 >Z"9rF2SW  
public void siteStop() 2FT-}w0;  
{ 4WG=m}X  
bStop = true; ]wf|PU~nr  
for(int i=0;i<nStartPos.length;i++) 4?]ZV_BD  
fileSplitterFetch.splitterStop(); *H*\gaSh  
'a_s%{BJXg  
dJE`9$j
N  
} -mC:r&Y>[  
} J!<#Nc  
//负责部分文件的抓取 ^Y<M~K972  
**FileSplitterFetch.java x\]z j!  
*/ 4tnjXP8  
package NetFox; ;_p fwa4  
\CwtX(6.  
j`Nh7+qs  
import java.io.*; ITQ9(W Un  
import java.net.*; kYtHX~@  
25&nwz  
-$m@*L  
public class FileSplitterFetch extends Thread { Zly-\z_  
3FY_A(+  
#nbn K  
String sURL; //File URL *+W6 P.K  
long nStartPos; //File Snippet Start Position ;"SZ}  
long nEndPos; //File Snippet End Position oB}K[3uB:t  
int nThreadID; //Thread's ID %t{Sb4XZ4k  
boolean bDownOver = false; //Downing is over ^\{J5  
boolean bStop = false; //Stop identical ~zj"OG"zOw  
FileAccessI fileAccessI = null; //File Access interface i\vpGlx  
|Z!@'YB  
j`hNZ%a  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 59~FpjJ  
{ c-`37. J  
this.sURL = sURL; ~K%k 0kT  
this.nStartPos = nStart; c+wuC,  
this.nEndPos = nEnd; ?4MSgu  
nThreadID = id; ZGzc"r(r:#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IuDT=A  
} \d ui`F"Cc  
{sl~2#,}b1  
F6DxvyANr  
public void run() MN\i
-vAL8  
{ |F
jBKj  
while(nStartPos < nEndPos && !bStop) C~{xL>I  
{ wF
p~  
cNx \&vpd  
xl|ghjn  
try{ 'Z59<Ya&x  
URL url = new URL(sURL); A0UV+ -PP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P:>'   
httpConnection.setRequestProperty("User-Agent","NetFox"); {[my"n2  
String sProperty = "bytes="+nStartPos+"-"; 9}.,2JE  
httpConnection.setRequestProperty("RANGE",sProperty); fJvr+4i4k  
Utility.log(sProperty); n}VbdxlN  
ypgliq(  
4v0dd p  
InputStream input = httpConnection.getInputStream(); ~d&'Lp[3  
//logResponseHead(httpConnection); 5d>nIKW  
vwm|I7/w  
f 5mY;z"  
byte[] b = new byte[1024]; o@Scz!"g  
int nRead; U
.Pa7tn  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i
x(U:'{  
{ cO8`J&EK  
nStartPos += fileAccessI.write(b,0,nRead); l&\tf`~  
//if(nThreadID == 1) 3L?WTS6(u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H U:1f)aa  
} '_k>*trV  

wEZ,49  
>-UD]?>  
Utility.log("Thread " + nThreadID + " is over!"); H]Y#pLu|  
bDownOver = true; i<'
{Y  
//nPos = fileAccessI.write (b,0,nRead); ~K4k'   
} $,}Qf0(S  
catch(Exception e){e.printStackTrace ();} 7zOhyl?  
} h_AJI\{"  
} #8S [z5 `  
2;dM:FHLhO  
7qW.h>%WE  
//打印回应的头信息 u![4=w  
public void logResponseHead(HttpURLConnection con) FP.(E9  
{ u4go*#  
for(int i=1;;i++) rat=)n)"t  
{ 'Na|#tPYI  
String header=con.getHeaderFieldKey(i); (qNco8QKu3  
if(header!=null) Up_>y>x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ngn\nkf  
Utility.log(header+" : "+con.getHeaderField(header)); 7^n,Tig  
else &*X3
ch  
break; (PRaiE  
} s4!|v`+$M  
} nrxjN(9V%+  
#&;m<%  
N;e;
4,_ n  
public void splitterStop() rdORNlK&  
{ s4MNVT  
bStop = true; 'hxs((['\  
} (3)C_Z  
QBg}2.  
-fb1cv~N  
} /E=h{|  
nwZ[Ygl|  
c2tEz&=G  
/* ~r(g|?}P  
**FileAccess.java _bN))9 3  
*//文件访问(定位，写) <1ztj
#B  
package NetFox; !O 0ZD4/{4  
import java.io.*; 34"{rMbQ  
?q
+8 /2  
{LR#(q$1  
public class FileAccessI implements Serializable{ 0S)"Q^6ny  
Hj}g1"RA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MsN2A6|33  
RandomAccessFile oSavedFile; Z\ "Kd  
long nPos; 3MS3O.0]/  
j<. <S {  
7AZ5%o  
public FileAccessI() throws IOException 6Y0/i,d*  
{ ?7r
mwy\  
this("",0); {jj]K
.&  
} ;`X`c  
J>,'P^  
|U;w!0  
public FileAccessI(String sName,long nPos) throws IOException v*vub#wP  
{ D'HL /[@`  
oSavedFile = new RandomAccessFile(sName,"rw"); ` 4s#5g  
this.nPos = nPos; >=Rd3dgDG  
oSavedFile.seek(nPos); bAA'=z<  
} d +*T@k]>M  
17MN8SfQ  
*so6]+)cU  
public synchronized int write(byte[] b,int nStart,int nLen) Xm_Ub>N5  
{ =RCfibT!C  
int n = -1; ;/6:lL  
try{ {,n
d_3"Vq  
oSavedFile.write(b,nStart,nLen); |THkS@Br  
n = nLen; @j)f
(Zlu#  
} /NPl2\o.  
catch(IOException e) >tE
,8  
{ E-*>f"<h  
e.printStackTrace (); +oxqS&$L  
} FvtM~[Q  
jk WBw.(  
 RU3_Fso  
return n; "GIg|3  
} [4V|UvKz  
bi4^ zaCEE  
ijR-?nrR  
} ss|6_H =  
VC_3ll]vr  
;&7qw69k  
/* .{-iq(3  
**SiteInfoBean.java +#i,87  
*/ JsAb q  
package NetFox; +E""8kW- Z  
LiHXWi{s  
r`mzsO-'  
public class SiteInfoBean { +ik N) D  
b_)QBE9  
{4V:[*
3  
private String sSiteURL; //Site's URL &L[8Mju6  
private String sFilePath; //Saved File's Path qZyt>SAx  
private String sFileName; //Saved File's Name y7}~T!UyfF  
private int nSplitter; //Count of Splited Downloading File 2_ZHJ,r   
IAt+S-q0  
N8/Au=De_  
public SiteInfoBean() Ed ?Yk* 4  
{//nSplitter的缺省值为5 |?pYJkrYO  
//default value of nSplitter is 5 <7RkM
 
this("","","",5); l")o!N?  
} Nt,]00S\w  
Q>+_W2~]  
hH|XtQ.n^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s]V{}bY`  
{ $yxIE}  
sSiteURL= sURL; <)0LwkFtB  
sFilePath = sPath; 4^jZv$l5  
sFileName = sName; plz=G}Y  
this.nSplitter = nSpiltter; U`vt/#j 1  
:`!mCW`Q-  
9Rt(G_'  
} nu1w:  
 hE?GO,  
./5MsHfbxt  
public String getSSiteURL() sB*h`vs0T  
{ [))2u:tbS\  
return sSiteURL; 'KW+Rr~tZn  
} 7u&H*e7  
a7 '\*  
=fu_ Jau}  
public void setSSiteURL(String value) 0^-b}  
{ iaq:5||,  
sSiteURL = value; Ug[F3J|Mu  
} p_kTLNZd9  
9BgQoK@  
cR@
}   
public String getSFilePath() :[$i~V  
{ u{y5'cJ{  
return sFilePath; {3yws4  
} RWEgUDX^/  
lf7H8k,-  
rO2PbF3  
public void setSFilePath(String value) fe]T9EDA  
{ ^dp[Z,[1z  
sFilePath = value; Ni;{\"Gt  
} nqw*oLFQ  
&b#NF1Q.  
i~M.F=I5  
public String getSFileName() {
UjIxV(J  
{ N'1[t  
return sFileName; ,hcBiL/  
} ?)ZLxLV::  
,\">ovV33  
k?_$h<Y  
public void setSFileName(String value) ;:K?7wfXn  
{ MJk:s[o  
sFileName = value; ^<H#dkECG  
} <MDFfnj  
c9TkIe  
>5YYij5Aj  
public int getNSplitter() s!zr>N"  
{ 1,sO =p)Yg  
return nSplitter; m0K2p~  
} uc `rt"  
ieK'<%dxF  
}N=zn7W  
public void setNSplitter(int nCount) pz z`4VS:  
{ 6-E4)0\  
nSplitter = nCount; sRI=TE]s  
} 4?6'~G$k  
} \}_7^)S;  
L``mF(R^  
=dJEcC_J  
/* Mdq'> <ajL  
**Utility.java N_~Wu  
*/ v,
O&UrZ  
package NetFox; 4iB)oR  
Ymh2qGcj]8  
UHm+5%ZC  
public class Utility { L&F\"q9q71  
;@$,
" P  
nHL>}Yg  
public Utility() pl? J<48  
{ SF}L3/C&h  
kA$;vbm  
>w'?DV>u|  
} gbi~!S-  
w[7HY@[  
//线程睡眠 l=G#gKE  
public static void sleep(int nSecond) 4rCqN.J  
{ qv >(  
try{ !!Gi.VL
 
Thread.sleep(nSecond); vnT  
} G7#~=W 2M  
catch(Exception e) xn#I7]]G  
{ -)c"cgx.  
e.printStackTrace (); ^.aEKr  
} oHGf |  
} +]2~@=<@  
o]k]pNO  
//日志 2H0q\zZ  
public static void log(String sMsg) "VhrsVT  
{ z[I/ AORl  
System.err.println(sMsg); %.}  
} %1l80Z  
st^N QL  
UVi/Be#|  
public static void log(int sMsg) 9(\N+  
{ I;PO$T  
System.err.println(sMsg); d3hTz@JY  
} GoGgw]h>x  
} N1zrfn-VU  
LWR&(p.%  
-|UX}t*  
/* }E]&13>r  
**TestMethod.java 2G*#Czr"  
*/ `e:RZ
  
package NetFox; UmMYe4LQR  
g0U\AN  
X_yU"U  
public class TestMethod { :BiR6>1:  
))-M+CA  
Fd=`9N9  
public TestMethod() N`:bvr  
{ ///xx/weblogic60b2_win.exe `'t;BXedz/  
try{ <OFqUp*l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 23?0'AU  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]t0S_UH$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); J:!Gf^/)  
fileFetch.start(); i(#c Yb  
} rm;"98~zJ?  
catch(Exception e){e.printStackTrace ();} , X+(wp  
ed2&9E>9b  
x@l~*6!K  
} |Y8o+O_`  
M/I d\~  
|I<-x)joIK  
public static void main(String[] args) 0p2O8>w^%  
{ 4B,A+{3yL  
new TestMethod(); / =<ul-K  
} tUnVdh6L.B  
} y.NArN|%  
点击下载更多相关资料