http断点续传简单实现（java)

/* :VPZGzK4  
**SiteFileFetch.java A22h+8yG  
*/ Og`6>?>97  
package NetFox; > dJvl|  
import java.io.*; zkdyfl5  
import java.net.*; NU*6MT4  
CL*i,9:NR  
-Fodqq@,  
public class SiteFileFetch extends Thread { TR8
<=  
9=D\xBd|w  
r*K[,  
SiteInfoBean siteInfoBean = null; //文件信息Bean
/q4<ZS#  
long[] nStartPos; //开始位置 A0SEzX({[  
long[] nEndPos; //结束位置 *dn~-W.  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 l@FPTHq  
long nFileLength; //文件长度 Uhc2`r#q  
boolean bFirst = true; //是否第一次取文件 \v7M`! &  
boolean bStop = false; //停止标志 ?Sj3-*/?  
File tmpFile; //文件下载的临时信息 C>q,c3s5  
DataOutputStream output; //输出到文件的输出流 (~Pb,Q  
nV-A0"z_&  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） O|J`M2r  
public SiteFileFetch(SiteInfoBean bean) throws IOException AF4:v<EN  
{ hL#5:~(  
siteInfoBean = bean; )miY>7K  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); nz:I\yA  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 'W5r(M4U  
if(tmpFile.exists ())  T|NNd1>  
{ 12*'rU;*  
bFirst = false; agqB#,i  
read_nPos(); q;a`*gX^  
} P SDzs\s  
else ;7"}I  
{ klduJT >  
nStartPos = new long[bean.getNSplitter()]; V-U,3=C  
nEndPos = new long[bean.getNSplitter()];  $9dm2#0d  
} Y,OS
QBgk  
9^Q:l0|  
cg$@x\fJ  
PR=:3-#R  
} <JE-#i  
$Scb8<  
(.,`<rXw  
public void run() )&}\2NK6L  
{ $E@L{5Yt  
//获得文件长度 U7d%*g  
//分割文件 B#'TF?HUEn  
//实例FileSplitterFetch 2Q`@lTUv  
//启动FileSplitterFetch线程 h% BA,C  
//等待子线程返回 iva&W  
try{ 8munw  
if(bFirst) qt5CoxeJ  
{ xg~q'>
 
nFileLength = getFileSize(); K2,oP )0.Y  
if(nFileLength == -1) v]|^.x:  
{ ,@ A1eX}  
System.err.println("File Length is not known!"); _sIhQ8$:  
} E\Hhi.-  
else if(nFileLength == -2) L@Fw;G|%'  
{ ^OKCvdS  
System.err.println("File is not access!"); 2@ vSe  
} hM^#X,7  
else !0:uM)_k  
{ PLR[nB7K  
for(int i=0;i<nStartPos.length;i++) qy=4zOOD#  
{ e`ti*1]q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); YIo$  
} \G}EI|Wo  
for(int i=0;i<nEndPos.length-1;i++) o5KpiibFM  
{ }
z6@Z#%q  
nEndPos = nStartPos[i+1]; &1Dq3%$c  
} /n;-f%dL  
nEndPos[nEndPos.length-1] = nFileLength; S05+G}[$  
} +@[T0cXp  
} =4cK9ac  
|f1 S&b.  
:GXiA  
//启动子线程  f.acH]p  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |Fz/9+I  
for(int i=0;i<nStartPos.length;i++) 'PRsZ`x.  
{ [2I1W1pd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c'nEbelE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4E]w4BG)  
nStartPos,nEndPos,i); Q!8AFLff4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dC8$Ql^<  
fileSplitterFetch.start(); *4#)or  
} O?e38(
 
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AE!DftI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {]1o($.u  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Jm&7&si7  
nEndPos = " + nFileLength); S0().2#  
// fileSplitterFetch[nPos.length-1].start(); rZ`ob x\S  
v3!oY t:l  
:N$^x /{  
//等待子线程结束 qYFOHu  
//int count = 0; eMyh&@7(F  
//是否结束while循环 .%;`:dtj  
boolean breakWhile = false; ^
=:e9i3u  
4ti\;55{W  
!$
N^Ak5#  
while(!bStop) A\p'\@f  
{ `|?K4<5
|  
write_nPos(); R:c$f(aKv%  
Utility.sleep(500); G"P@AOw  
breakWhile = true; o1C1F}gxU  
x`n$4a'7b  
F]]1>w*/0  
for(int i=0;i<nStartPos.length;i++) ?O3E.!Q|  
{ aphfzo  
if(!fileSplitterFetch.bDownOver) 2noKy}q  
{ ybLl[K(D=  
breakWhile = false; &Omo\Oq&W>  
break; iAD'MB  
} Wno{&I63  
} Y,BzBUWK  
if(breakWhile) jb;!"HC  
break; dqF]kP,VG  
"Bl]_YPv  
BUcPMF%\y:  
//count++; ]}7FTMGbY  
//if(count>4) P^9y0Q  
// siteStop(); 32h}+fd  
} zq]I"0Bi.  
fz/Ee1T\  
o/0cd  
System.err.println("文件下载结束！"); WUOoK$I~K  
} U9w0kcUw#J  
catch(Exception e){e.printStackTrace ();} @bs YJ4-V  
} A|jmp~@K)+  
^h wF=  
[+,%T;d;  
//获得文件长度 =iJ
fz  
public long getFileSize() +xoh=m  
{ &1
nZ%J9  
int nFileLength = -1; r~f*aD  
try{ k;EG28   
URL url = new URL(siteInfoBean.getSSiteURL()); q!UN<+k\h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \Af25Mcf:  
httpConnection.setRequestProperty("User-Agent","NetFox"); pO]{Y?X:  
]QM{aSvXA  
<'(O0  
int responseCode=httpConnection.getResponseCode(); nsf.wHGZ"J  
if(responseCode>=400) Nf@-i`  
{ KWuc*!  
processErrorCode(responseCode); 'v|R' wi\  
return -2; //-2 represent access is error 87&BF)]  
} .T!R&#]n  
}jL_/gvgy  
5&Y%N(  
String sHeader; Cu2eMUGt  
:vsBobi
J  
0EWov~Y?  
for(int i=1;;i++) ]IF QD  
{ +=_^4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KImBQ2^Tu  
//Utility.log(in.readLine()); He&7(mQ0^  
sHeader=httpConnection.getHeaderFieldKey(i); 
VIIBw  
if(sHeader!=null) whH_<@!  
{ `5SLo=~  
if(sHeader.equals("Content-Length")) W#|30RU.G  
{ yM_ta '^$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f{i~hVF  
break; x6n
(BMr  
} G 51l_  
} Wi;wu*  
else OEZ`5"j  
break; 62-,!N 1-  
} ! .q,m>?+  
} vk:k~  
catch(IOException e){e.printStackTrace ();} DfPC@` k  
catch(Exception e){e.printStackTrace ();} <bvbfS  
$Gy&  
pxGDzU  
Utility.log(nFileLength); K3Sa6"U  
o$4i{BL  
uT Z#85L`  
return nFileLength; &
EUI  
} a+-X\qN  
vk1E!T9X  
YK{E=<:  
//保存下载信息（文件指针位置） },]G +L;R  
private void write_nPos() >b1#dEY  
{ 8*bEsc|  
try{ 6x.ZS'y  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $~;h}I  
output.writeInt(nStartPos.length); qOqU CRUe:  
for(int i=0;i<nStartPos.length;i++) H^d2|E[D  
{ nt:d,H<p  
// output.writeLong(nPos); JmP[9"  
output.writeLong(fileSplitterFetch.nStartPos); .#OD=wkN0  
output.writeLong(fileSplitterFetch.nEndPos); f{HjM? Mb3  
} /0_^Z2  
output.close(); xHpB/P~  
} W'xJh0o  
catch(IOException e){e.printStackTrace ();} 
Lw1aG;5  
catch(Exception e){e.printStackTrace ();} /
19ZyQw9  
} =i1+t"
=  
T?4I\SG  
0XzrzT"&  
//读取保存的下载信息（文件指针位置） K2o\+t  
private void read_nPos() c$fYK  
{ \i.Yhl:O  
try{ =jWjUkm2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {/2 _"H3:  
int nCount = input.readInt(); FhFP M)[  
nStartPos = new long[nCount]; lh]Q\  
nEndPos = new long[nCount]; #*tWhXU  
for(int i=0;i<nStartPos.length;i++) ytyX:e"  
{ S)\Yc=~h  
nStartPos = input.readLong(); Ve9*>6i&-4  
nEndPos = input.readLong(); [h0.k"&[  
} = lMs1}S9  
input.close(); 3*C|"|lJ  
} *=)kR7,]9d  
catch(IOException e){e.printStackTrace ();} 6V&HlJH  
catch(Exception e){e.printStackTrace ();} K9=f`JI9  
} #\T5r*W  
L3J .Oh  
"V3f"J?  
private void processErrorCode(int nErrorCode) nsjrzO79L8  
{ YsA.,  
System.err.println("Error Code : " + nErrorCode); "~,3gNTzV  
} OaF[t*]D3  
*t_JR  
V+>.Gf  
//停止文件下载 qgkC
)
  
public void siteStop() "eH.<&  
{ \sc's7  
bStop = true; caD|*.b  
for(int i=0;i<nStartPos.length;i++) @E !`:/k
 
fileSplitterFetch.splitterStop(); %<yH6h*u  
1MYA/l$  
kNC]q,ljt5  
} uD8,E!\  
} .[:2M9Rx  
//负责部分文件的抓取 i"GCm`  
**FileSplitterFetch.java q6AL}9]9  
*/ "]kq,j^]  
package NetFox; iT,Ya-9"  
x~n]r[!L  
JL:\\JT.  
import java.io.*; *<#$B}!{  
import java.net.*; th]pqhl>  
D]*<J"/]d  
MgrJ ;?L  
public class FileSplitterFetch extends Thread { K['Gp>l  
aC,?FWm  
a8v9j3.  
String sURL; //File URL hw)#TEt   
long nStartPos; //File Snippet Start Position p#+Da\qmx  
long nEndPos; //File Snippet End Position tXW7G@  
int nThreadID; //Thread's ID yd~}CF  
boolean bDownOver = false; //Downing is over SY$%)(c8kL  
boolean bStop = false; //Stop identical iHlee=}od  
FileAccessI fileAccessI = null; //File Access interface ^c?$$Tq  
n7pjj  
C^7M>i  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +k\cmDcb  
{ _bSn YhS  
this.sURL = sURL; `c?8i  
this.nStartPos = nStart; @waY+sqt=  
this.nEndPos = nEnd; 3Uy(d,N  
nThreadID = id; q+W*?a)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xk}\-&C7  
} jf=\\*64r4  
 >f*Zf(F  
gXe`G(w  
public void run() \?"p]&2UcB  
{ cBQ+`DXn5c  
while(nStartPos < nEndPos && !bStop) TV~S#yg+H  
{ U:uFrb,  
o "1X8v  
y=LN|vkQ  
try{ g)nT]+&  
URL url = new URL(sURL); ]K|td)1X  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G<Y}QhFU  
httpConnection.setRequestProperty("User-Agent","NetFox"); K[l5=)G0L  
String sProperty = "bytes="+nStartPos+"-"; 'M,O(utGv  
httpConnection.setRequestProperty("RANGE",sProperty); BVu{To:g  
Utility.log(sProperty); [}`-KpV!;  
DVjwY_nG7  
jbp?6GW  
InputStream input = httpConnection.getInputStream(); Rk!8eN Pf  
//logResponseHead(httpConnection); mZ~f
?{  
75eZhs[b  
Kon|TeC>d  
byte[] b = new byte[1024]; mq+<2 S  
int nRead; T+41,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [wn! <#~v  
{  NR98]X  
nStartPos += fileAccessI.write(b,0,nRead); Y=Om0=v  
//if(nThreadID == 1) Z31a4O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gjn1ha"h%.  
} </D )i  
ei(S&u<  
-l?\hmDl  
Utility.log("Thread " + nThreadID + " is over!"); xM![  
bDownOver = true; mX[J15  
//nPos = fileAccessI.write (b,0,nRead); V#X<Yt  
} sBLOrbo  
catch(Exception e){e.printStackTrace ();} Dq+S'x~>  
} vQy+^deW  
} gjk;An  
Y6m:d&p=}  
@.L/HXu-P  
//打印回应的头信息 lr]C'dD  
public void logResponseHead(HttpURLConnection con) ]A:8x`z#F  
{ C(kL
=WD   
for(int i=1;;i++) Y(=A HmR  
{ i':a|#e>  
String header=con.getHeaderFieldKey(i); Q^):tO]!Ma  
if(header!=null) L| ;WE=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TT={>R[B  
Utility.log(header+" : "+con.getHeaderField(header)); 7G%:ckg  
else +0)H~ qB\  
break; DB(!*6#?  
} LIn2&r:U  
} d;i@9+  
ZqXp f  
EAlLxXDDh  
public void splitterStop() -6$GM J7  
{ k:URP`w[X=  
bStop = true; 1rON8=E  
} <u/(7H
 
AF>t{rw=/  
u:H:N]  
} }s[`T   
@@cc
/S  
EI496bsRHm  
/* k"6&&  
**FileAccess.java &@=W+A=c~  
*//文件访问(定位，写) ""*g\  
package NetFox; =|dHD  
import java.io.*; b@O{eQB  
{nw.bKq7  
q
g:EN~E#  
public class FileAccessI implements Serializable{ sG\K$GP!  
u<4bOJn({  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OY2u,LF9H  
RandomAccessFile oSavedFile; 4W}mPeEeV  
long nPos; kK/XYC 0D  
s6'=4gM  
?!O4ia3nFk  
public FileAccessI() throws IOException "BZ@m:I6hy  
{ v]Aop<KLX  
this("",0); a?4'',~  
} eyq8wQT  
1+1Z]!nG#!  
oe<9CK:?>  
public FileAccessI(String sName,long nPos) throws IOException 6I0
G.N  
{ 0Q^a*7w`8a  
oSavedFile = new RandomAccessFile(sName,"rw"); ? Xb8B5  
this.nPos = nPos; 2R:I23[#B  
oSavedFile.seek(nPos); M_wqb'=  
} N/ 7Q(^  
Pqe{C?7B  
=Ri'Prx&  
public synchronized int write(byte[] b,int nStart,int nLen) s8,{8k  
{ M_-LI4>  
int n = -1; B3Id}[V  
try{ 0/7y&-/(  
oSavedFile.write(b,nStart,nLen); 8`e75%f:2  
n = nLen; %UEV['=  
} 5$kv,%ah  
catch(IOException e) |a7W@LVYD  
{ <ob+Ano$  
e.printStackTrace (); 9[<,49  
} RrMC[2=  
Za+26#g  
&|t*9D  
return n; ?n$;l-m[  
} P I gbeP  
Vx1xULdY  
X{SD3j=G#  
} q$[x*!~  
2jQ|4$9j  
&5Ai&<q"p  
/* s`2Hf&%aZJ  
**SiteInfoBean.java :b^\O  
*/ %M+ID['K9/  
package NetFox; MjIp~?*

 
92}UP=RW!  
Vj^<V|=  
public class SiteInfoBean { vh8{*9+  
A;~u"g'z&  
+we3BE.  
private String sSiteURL; //Site's URL w!{g^*R+!  
private String sFilePath; //Saved File's Path `@MY}/ o.  
private String sFileName; //Saved File's Name 8+5-7)  
private int nSplitter; //Count of Splited Downloading File (/J$2V5-  
5;=,BWU  
!"\UT&  
public SiteInfoBean() wy3{>A Z(  
{//nSplitter的缺省值为5 w{$t:l)2,  
//default value of nSplitter is 5 9OYsI
 
this("","","",5); vJg|}]h>L  
} }a= &o6=  
.VF4?~+M-  
yQ)y#5/<6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0*?~I;.2m$  
{ 9N^&~O|1  
sSiteURL= sURL; YKbR#DC\  
sFilePath = sPath; !@E=\Sm8EV  
sFileName = sName; kJP fL s  
this.nSplitter = nSpiltter; ?YR/'Vq97  
D.G+*h@ g  
Lx&2)  
} mO$]f4}  
J[fjl6p  
Q8.SD p  
public String getSSiteURL() w]w>yD>$  
{ M|e Qds  
return sSiteURL; <6k5nEh  
} h@$M.h@mcG  
:4|W;Lkd!  
mq@2zE`.(  
public void setSSiteURL(String value) Y2i:ZP  
{ e=KA|"vxh  
sSiteURL = value; :Mr_/t2(  
} mx s=<  
FVkb9(WW  
?[Xv(60]  
public String getSFilePath() F3/aq+<P[  
{ ES72yh]  
return sFilePath; &d]%b`EXq  
} xcfEL_'o  
xMI4*4y(  
[@MV[$W5  
public void setSFilePath(String value) Ij>IL!  
{ >pjmVlw?  
sFilePath = value; -7)%J+5  
} fvKb0cIx]  
_SM5x,Zd  
(i4=}Kn2  
public String getSFileName() &VtTUy}  
{ {Lu-!}\NP  
return sFileName; 7!Z\B-_,  
} n@[&SgZq  
D. !m*oq  
k4iu`m@^H  
public void setSFileName(String value) isK~=  
{ s"b()JP  
sFileName = value; -.=q6N4  
} t?H.M  
490gW?
u  
7r,'a{Rcn  
public int getNSplitter() ;=piJ%k  
{ x]|8  
return nSplitter; =qH9<,p`H  
} ,Oojh;P_  
"TB4w2?=  
"5*n(S{ks  
public void setNSplitter(int nCount) +#~=QT9  
{ j&n][=PL  
nSplitter = nCount; e _\]Q-  
} 5&]|p'"W\  
} |&vQ1o|}  
Zp~2WJQ  
^znj
J\  
/* MkJ}dncg*  
**Utility.java Ek\fx*Lz  
*/ Qzy[  
package NetFox; [wB-e~  
No8~~  
1{\{'EP{  
public class Utility { Ezw(J[).C  
'~i;g.n=}-  
udxLHs  
public Utility() lk8g2H ,  
{ ]Cd1&  
q H&7Q{  
j3 d=O!  
} DueQ1+ P  
J5Rr7=:*S  
//线程睡眠 Rz% Px:M  
public static void sleep(int nSecond) `F<)6fk  
{ ]UyIp`nV;  
try{ gzqx{ ]  
Thread.sleep(nSecond); z#*M}RR  
} Rfh#JO@%[  
catch(Exception e) ^L}fj$  
{ et]-;(M  
e.printStackTrace (); -Si'[5@  
} iyNyj44 H  
} Hb5^+.xur  
`[\*1GpAo  
//日志 /zZ$<mVG  
public static void log(String sMsg) >QRpRHtb  
{ h-`Jd>u"  
System.err.println(sMsg); J
\U}U'qP  
} 8XtZF,Du  
VgG*y#Qf$  
g+8{{o=  
public static void log(int sMsg) 3DRbCKNL  
{ T'.U?G  
System.err.println(sMsg); vH_QSx;C#  
} YGrmco?G  
} dK|6p_  
?,e7v.b
 
`
oN~  
/* vwQY_J8  
**TestMethod.java A2 r1%}{  
*/ 4eapR|#T  
package NetFox; ?_36uJo}  
A,-UW+:  
SPKGbp&  
public class TestMethod { ?H8w/{J   
A `\2]t$z  
[/uqH  
public TestMethod() $h1`-=\7  
{ ///xx/weblogic60b2_win.exe yQb^]|XG  
try{ {>[,i`)  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nWpqAb  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0eq="|n^|  
SiteFileFetch fileFetch = new SiteFileFetch(bean); qk~ni8  
fileFetch.start(); W6f?/{Oo8  
} `` (D01<  
catch(Exception e){e.printStackTrace ();} :3WrRT,'L  
5Z{i't0CQ  
hX4&B  
} vU&I,:72 H  
2Jo'!|]  
D?~`L[}I!}  
public static void main(String[] args) tqyR~  
{ >#).3  
new TestMethod(); IB#L5yN r  
} GkqKIs  
} F VBuCi?W  
点击下载更多相关资料