http断点续传简单实现（java)

/* E3S0u7Es  
**SiteFileFetch.java 7vPGb:y  
*/ .HY,'oC.  
package NetFox; It/'R-H  
import java.io.*; Y~^R^J  
import java.net.*; $;ny`^8  
|p
*cI @  
{*hGe_^  
public class SiteFileFetch extends Thread { {y@8E>y5$  
_hJ+8B^`  
OC,yLQ  
SiteInfoBean siteInfoBean = null; //文件信息Bean 94 6r#`q  
long[] nStartPos; //开始位置
e"sv_$*  
long[] nEndPos; //结束位置 #;8VBbc\^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 vOKNBR2  
long nFileLength; //文件长度 oo]P}ra  
boolean bFirst = true; //是否第一次取文件 (?,jnnub  
boolean bStop = false; //停止标志 ESIJ QM-[+  
File tmpFile; //文件下载的临时信息 _f>)G3p  
DataOutputStream output; //输出到文件的输出流 .@;5"  
TZ n2,N  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） sLTQm*jL  
public SiteFileFetch(SiteInfoBean bean) throws IOException qycf;Kl:6  
{ vzSjfv  
siteInfoBean = bean; Bmt8yR2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); YT[=o}jS  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ft{i6}  
if(tmpFile.exists ()) L?8OWLjRy  
{ k{X+Y6'ku  
bFirst = false; G^L9[c= ,  
read_nPos(); w0sy@OF  
}  C.uv
0  
else oGeV!hD  
{ rB(Q)N  
nStartPos = new long[bean.getNSplitter()]; ,:-^O#  
nEndPos = new long[bean.getNSplitter()]; }>,%El/  
} u0?TMy.%  
>N`, 3;Z  
0%\fm W j  
"[z/\l8O  
} Q-G8Fo%#,E  
N@'l:N'f4  
'MyJw*%b]  
public void run() WyQ8}]1b  
{ ,_7m<(/f  
//获得文件长度 X>yE<ni  
//分割文件 {~g7&+9x*
 
//实例FileSplitterFetch Z!'kN\z  
//启动FileSplitterFetch线程 2.{<C.BK{  
//等待子线程返回 l)DcwkIG  
try{ hlc g[Qdo*  
if(bFirst) %Y|AXxR  
{ NX;{L#lQ  
nFileLength = getFileSize(); BjjuZN&  
if(nFileLength == -1) w}07u5
 
{ Ut1s~b1  
System.err.println("File Length is not known!"); }p)a7xn}  
} yVPFH~1@\  
else if(nFileLength == -2) WoSKN7*  
{ %%wngiz\  
System.err.println("File is not access!"); nddCp~NX  
} ecvZwL  
else qM^y@B2MO
 
{ 0f+]I
=1\  
for(int i=0;i<nStartPos.length;i++) y^{4}^u-^  
{ oc-o>H  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); s1%2({wP  
} l<"B[  
for(int i=0;i<nEndPos.length-1;i++) G[zysxd  
{ mkBQTQGT  
nEndPos = nStartPos[i+1]; .rDao]K  
} 8|hi2Qeu,c  
nEndPos[nEndPos.length-1] = nFileLength; "4*QA0As  
} cZWW[i  
} 4l/~::y  
.Z17X_  
4h}\Kl  
//启动子线程 IL*MB;0>  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9/#b1NGv  
for(int i=0;i<nStartPos.length;i++) hSh^A5 /  
{ `I|Y7GoUO  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cIuCuh0I`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aH500  
nStartPos,nEndPos,i); +$^[r  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [R~@#I P!  
fileSplitterFetch.start(); M&/e*Ta5  
} hNp.%XnnZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3VQmo\li  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oye/tEMG  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d;r,?/C  
nEndPos = " + nFileLength); Z\)P|#L$  
// fileSplitterFetch[nPos.length-1].start(); yW"}%) d  
,zBc-Cm  
^M1O)   
//等待子线程结束 xkaed  
//int count = 0; 7tY~8gQel  
//是否结束while循环 itO1ROmu  
boolean breakWhile = false; sQT,@+JEr  
%Si3LQf  
7 :u+-U  
while(!bStop) yN}<l%  
{ Z>'hNj)ju  
write_nPos(); MB.LHIo  
Utility.sleep(500); DsBZ%  
breakWhile = true; t{ridA}  
!6s]p%{V  
JQ\o[t  
for(int i=0;i<nStartPos.length;i++) 2 t]=-@  
{ @c,=c+-  
if(!fileSplitterFetch.bDownOver) @oMl^UYM=  
{ 5pE@Ww  
breakWhile = false; .Ag)/Xm(?  
break; yv5c0G.D  
} XToYtdt2  
} <,nd]a  
if(breakWhile) 7^h*rL9  
break; V}G;oz&>)  
.ityudT<  
&gvX<X4e  
//count++; mgEZiAV?  
//if(count>4) =Ajw(I[56  
// siteStop(); Cz4l  
} M""X_~&I"  
79M`?xm  
y;LZX-Z-  
System.err.println("文件下载结束！"); ?kc,}/4  
} 7I6&*I  
catch(Exception e){e.printStackTrace ();} pkA(\0E8  
} tpKQ$)ed  
<UJ5n) }"\  
&)Iue<&2  
//获得文件长度 5kj=Y]9\I  
public long getFileSize() {E>(%vD  
{ :UsNiR=l  
int nFileLength = -1; 8DlRD$_:&  
try{ of.=n  
URL url = new URL(siteInfoBean.getSSiteURL()); &R}2/Mt  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /vFdhh  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]<E\J+5K  
k5GJrK+  
`"E<%$|ZQy  
int responseCode=httpConnection.getResponseCode(); xTdh/}  
if(responseCode>=400) cU=EXyP%  
{ HBgt!D0MZ  
processErrorCode(responseCode); :B4X/  
return -2; //-2 represent access is error |Iq\ZX%q  
} QEq>zuz5;  
Y3f2RdGl  
>K;C?gHo  
String sHeader; ljj}XJQ  
:U#4H;kk~j  
0o&7l%Y/  
for(int i=1;;i++) pd}af iF  
{  0GiL(e|  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); & Pzr)W(  
//Utility.log(in.readLine()); '[Ch8
Yf\  
sHeader=httpConnection.getHeaderFieldKey(i); Y!nE65  
if(sHeader!=null) KZTT2KsYl  
{ SNf*2~uq)  
if(sHeader.equals("Content-Length")) x-s]3'!L  
{ Y-:{a1/RKo  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sBu- \P#  
break; A!!W\Jt  
} yi3Cd@t({{  
} t[^68]  
else @{UtS2L  
break; l8ZzKb-  
} &]HY:  
} 1'[_J  
catch(IOException e){e.printStackTrace ();} td
B<  
catch(Exception e){e.printStackTrace ();} \*$''`b)j  
M&K'5G)7  
PaYsn *{})  
Utility.log(nFileLength); 5J8U] :Y)  
Qa=v }d-O  
xD<:'-ri>  
return nFileLength; +}0/ %5 =1  
} D[ (A`!)  
+&hd3  
JN-wToOF  
//保存下载信息（文件指针位置） IHtNaN )  
private void write_nPos() c2<JS:!*  
{ Qf}b3WEAI  
try{ ^iaG>rvA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); VKp
4FiI6  
output.writeInt(nStartPos.length); 0')O4IHH  
for(int i=0;i<nStartPos.length;i++) b7h0V4w  
{ $@cg+Xrg1  
// output.writeLong(nPos); OfGMeN6  
output.writeLong(fileSplitterFetch.nStartPos); p+bT{:  
output.writeLong(fileSplitterFetch.nEndPos); =E''$b?Em  
} 9.qjEe  
output.close(); H[&X${ap  
} vEIDf{  
catch(IOException e){e.printStackTrace ();} Fv"jKZPgzz  
catch(Exception e){e.printStackTrace ();} wqLY \  
} 8n^v,s>  
w{;esU  
Dy_Za.N2  
//读取保存的下载信息（文件指针位置） y0D
="2
)  
private void read_nPos() oO8V0VE\  
{ 7Z+4F=2ff  
try{ z tLP {q#  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4=E9$.3a  
int nCount = input.readInt(); SiyZq"  
nStartPos = new long[nCount]; ^ LTKX`p  
nEndPos = new long[nCount]; \-B8
`ah  
for(int i=0;i<nStartPos.length;i++)  Lx:O Dd  
{ 4 u!)QG  
nStartPos = input.readLong(); ~ g\GC  
nEndPos = input.readLong(); Gn_rf"  
} {@c)!%2$  
input.close(); xi2!__  
} hI{M?LQd  
catch(IOException e){e.printStackTrace ();} o%E^41
M7E  
catch(Exception e){e.printStackTrace ();} n2$(MDdL`  
} Ht Z3n"2  
G'sEbw'[  
s<t*g]0`/  
private void processErrorCode(int nErrorCode) P=%'2BQ{{  
{  k_;+z  
System.err.println("Error Code : " + nErrorCode); nDvj*lZF  
} El
$yM.M"  
#sK:q&/G`  
l|c#  
//停止文件下载 `}YCUm[SI  
public void siteStop() 3~7X2}qU  
{ .6m%/-whS  
bStop = true; 11s*C #  
for(int i=0;i<nStartPos.length;i++) D@5AI ](  
fileSplitterFetch.splitterStop(); ' ?3e1  
ivKhzU+  
YVMwb@|  
} GDgq 4vfj  
} V~> x\  
//负责部分文件的抓取 WML%yO\.;  
**FileSplitterFetch.java [h>RO55e  
*/ V]V~q ]  
package NetFox; a.r+>44M  
~hSr06IY  
ep-~;?  
import java.io.*; I'M,p<B  
import java.net.*; G:HPd.ay  
;-:Nw6 E  
8R;)WlLu=  
public class FileSplitterFetch extends Thread { :qbbo~U  
vnT'.cBB:^  
',o ,o%n  
String sURL; //File URL *-gd k9  
long nStartPos; //File Snippet Start Position _%` )cOr  
long nEndPos; //File Snippet End Position tw/~z2G  
int nThreadID; //Thread's ID G{,X_MZ%  
boolean bDownOver = false; //Downing is over cg-\|H1  
boolean bStop = false; //Stop identical 9 -\.|5;:  
FileAccessI fileAccessI = null; //File Access interface [f9U9.fR  
06FBI?;|=  
bF5mCR:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-wtNM%1#  
{ l0^~0xlED  
this.sURL = sURL; Gy+/P6  
this.nStartPos = nStart; Gf(|?" H  
this.nEndPos = nEnd; iB
 =R  
nThreadID = id; '+6Sk
Z  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p_x@FA(  
} nwOT%@nw  
BM_hW8&G  
\zA G#{  
public void run() |#p`mc%f~\  
{ L{py\4z'_  
while(nStartPos < nEndPos && !bStop) >}tm8|IHoo  
{ &&/2oP+z  
@j/UDM  
"Zo<$p3]  
try{ h/7m.p]  
URL url = new URL(sURL); ^h}xFiAV#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bG`aF*10)!  
httpConnection.setRequestProperty("User-Agent","NetFox"); dWhki|c  
String sProperty = "bytes="+nStartPos+"-"; 9"5J-a'  
httpConnection.setRequestProperty("RANGE",sProperty); ev}lb+pr)_  
Utility.log(sProperty); uAd4Zz  
z@Klj qN  
aNX M~;5~  
InputStream input = httpConnection.getInputStream(); EZ6\pyNB0#  
//logResponseHead(httpConnection); >l & N  
?U\@?@  
AATiI+\S  
byte[] b = new byte[1024]; Ifghyh<d  
int nRead; Rt &Oz!TQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8reis1]2S  
{ O_yk<  
nStartPos += fileAccessI.write(b,0,nRead); q97Z .o  
//if(nThreadID == 1) llbf(!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F|,_k%QP  
} v1s.j2T  
n]?KDID;  
eI%{/>  
Utility.log("Thread " + nThreadID + " is over!"); MGt[zLF9  
bDownOver = true; bqmb|mD  
//nPos = fileAccessI.write (b,0,nRead); 8|5ttdZ  
} z}>q/!q  
catch(Exception e){e.printStackTrace ();} ]kXiT Yg  
} k,p:!S(bl  
} /i'dhiG  
P4&3jQ[o  
i&%~:K*
  
//打印回应的头信息 -@6R`m=>  
public void logResponseHead(HttpURLConnection con) ^lB=O  
{ kj$Ks2!W  
for(int i=1;;i++) Hs}3c R}  
{ k[{h
$  
String header=con.getHeaderFieldKey(i); h!k[]bt5  
if(header!=null) =l7@YCj5c  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); - '<K_e
;  
Utility.log(header+" : "+con.getHeaderField(header)); I?2S{]!?  
else cPFs K*w  
break; p_^Jr*Mv  
} =;hz,+  
} it Byw1/  
(n4\$LdP-  
3`%]3qd}  
public void splitterStop() ljr?Z,R4  
{ U`G  
bStop = true; %\i OX|F_  
} fVb~j;  
>bwB+-lyL  
#(i9G^K  
} fD^$ y 8  
0Nvk|uI V[  
+v!%z(  
/* Zb p+b;  
**FileAccess.java RM\A$.5  
*//文件访问(定位，写) K{]9Yo  
package NetFox; zWN<"[agc  
import java.io.*; c#-o@`Po  
v- 793pr  
dF@m4U@L  
public class FileAccessI implements Serializable{ E79'<;K,zs  

Z1 7=g@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =tkO^  
RandomAccessFile oSavedFile; QD2;JI2  
long nPos; ]0Y5 Z)3:z  
3}Xf  
y\?T%g  
public FileAccessI() throws IOException 5]-q.A5m  
{ l2Gtw*i_I  
this("",0); $(3mpQAg  
} |n*nByL/  
kH.e"e  
^x BQ#p  
public FileAccessI(String sName,long nPos) throws IOException 4l2/eh]Hc(  
{ H ~VeY\:w  
oSavedFile = new RandomAccessFile(sName,"rw"); \LN!k-c  
this.nPos = nPos; -:$#koW  
oSavedFile.seek(nPos); >cTSX  
} C2X$bX"  
HX)oN8  
TJ_<21a  
public synchronized int write(byte[] b,int nStart,int nLen) }0y2k7^]  
{ nM<B{AR5^  
int n = -1; IBT1If3  
try{ j aU.hASj  
oSavedFile.write(b,nStart,nLen); rEoMj)~\4&  
n = nLen; bgk+PQ#S-  
} (aeS+d x  
catch(IOException e) 3Fu5,H EJ  
{ [C>>j;q%  
e.printStackTrace (); s*g`| E{M  
} n|p(Cb#G  
V6L0\  
wr) \G
J#>  
return n; iImy"$yX{  
} SsY:gp_  
3J3Yt`  
;4:[kv@  
} 9I|D"zXn  
dvW2X  

6T9?C|q  
/* 85}S8\_u  
**SiteInfoBean.java OsrHA  
*/ E',z<S  
package NetFox; es6]c%o:t^  
+jPJv[W  
WA?We7m$  
public class SiteInfoBean { kMz*10$gn  
P9W!xvV`w  
A)5;ae  
private String sSiteURL; //Site's URL .7<6 zG6J  
private String sFilePath; //Saved File's Path ?niv}/'%O  
private String sFileName; //Saved File's Name ns&3Dh(IVP  
private int nSplitter; //Count of Splited Downloading File x@p1(V.  
u]766<Z  
]YciLc(  
public SiteInfoBean() {0o,2]o!:  
{//nSplitter的缺省值为5 YXlaE=9bn  
//default value of nSplitter is 5 /a .XWfu  
this("","","",5); v;WfcpWq2  
} {hH8+4c7  
B>kVJK`X  
!r#36kO  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f;`7}7C  
{ 2Kmnt(>  
sSiteURL= sURL; riu_^!"Z_  
sFilePath = sPath; ~p!=w#/  
sFileName = sName; !^x;4@Ejm  
this.nSplitter = nSpiltter; d(_;@%p1X  
j9d^8)O,  
03?7kAI  
} J?$`Tnx^  
8=-/0y9,  
[W8"Mc|ve  
public String getSSiteURL() kZK1{  
{ KlGmO;k  
return sSiteURL; d1>L&3HKx  
} B
GrV,h^  
(^~0%1  
H?4t\pSS  
public void setSSiteURL(String value) KX^!t3l6  
{ t!&p5wJ*Q  
sSiteURL = value; !CUy{
nV  
} "MPr'3  
$lAQcG&Q  
:m[HUh  
public String getSFilePath() 3n)\D<f]#  
{ wlEmy.)H  
return sFilePath; 2~y<l
 
} 6sQY)F7p  
U:fGIEz{ZY  
p;<aZ&@O  
public void setSFilePath(String value) 9TUB3x^  
{ Ru~;awV?  
sFilePath = value; 'h#>@v> }  
} cR6Rb[9 N  
VfT@;B6ALF  
w?JM;'<AYQ  
public String getSFileName() 87-z=>IU  
{ w gkY\Q  
return sFileName; 5`FPv4
 
} A2%RcKY7  
p7p6~;P  
G<FB:?|  
public void setSFileName(String value) vVFT0_  
{ BMH?BRi  
sFileName = value; U1=]iG<%  
} Ol)
M0u  
Fvr$K*u  
S^7u`-  
public int getNSplitter() 303x|y  
{ wqF_hs(O  
return nSplitter; ~0YRWM;  
} `OHdo$Y9  
)5ev4Qf  
<y<   
public void setNSplitter(int nCount) ja%IGaH;s  
{ 2Xqa?ay0>  
nSplitter = nCount; 3RP\w~?  
} z]R% A:6K  
} *@fVogr^  
Q[&CtM  
X8 A$&  
/* +<^c2diX  
**Utility.java ZJOO*S  
*/ )P#xny2  
package NetFox; xsRu~'f  

uC5W1LyI  
p&lT! 5P!A  
public class Utility { PcEE@W9  
jP )VTk_  
/MbWS(RT  
public Utility() 1v'|%B;O  
{ K[[ 5H  
wF)g@cw  
"q7pkxEuJ  
} [W8?ww%qT  
w^)_Fk3  
//线程睡眠 qFwAzW
;"  
public static void sleep(int nSecond) {KqERS& g  
{ xF`O ehVA  
try{ .t
zQ hd>  
Thread.sleep(nSecond); gezZYP)d  
} i,mo0CSa  
catch(Exception e) iz:O]kI  
{ "[2D&\$  
e.printStackTrace (); znNv;-q  
} t}2M8ue(&  
} VcORRUp
 
HC RmW'  
//日志 I8XU '  
public static void log(String sMsg) _MzdbUb5,  
{ nT%<!/}!  
System.err.println(sMsg); s%@HchZ 1  
} AxiCpAS;J  
tybM3VA  
BF(Kaf;<t.  
public static void log(int sMsg) PaBqv]  
{ fK5iOj'Q  
System.err.println(sMsg); @i
az_;  
} ke5_lr(  
} WbHI>tt  
4FcY NJq  
Wq/0
}W.  
/* 2-DJ3OL]k  
**TestMethod.java %s#`Z [8,  
*/ M6
*8}\  
package NetFox; rE4qPzL  
rB-}<22.  
skBzwVW I  
public class TestMethod {
; d :i  
lKLb\F%  
"xE;IpO[  
public TestMethod() xi!R[xr1  
{ ///xx/weblogic60b2_win.exe m.>y(TI  
try{ 7w5 L?,a  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Vf`9[*j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cB2jf</  
SiteFileFetch fileFetch = new SiteFileFetch(bean); fXB64MNo  
fileFetch.start(); =d1i<iw?-  
}  4d )Q  
catch(Exception e){e.printStackTrace ();} C:P.+AU"`  
V1\x.0Fs  
T`r\yl}  
} 42 &m)  
S0mF%"  
@+^5ze\  
public static void main(String[] args) a+p_47 xa  
{ :~B'6b  
new TestMethod(); \t+q1S1  
} ]?j[P=\  
} =y1/V'2E  
点击下载更多相关资料