http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); W\Y 4%y}
} >&Lu0oHH
for(int i=0;i<nEndPos.length-1;i++) IQY#EyTb
{ [c )\?MWW
nEndPos = nStartPos[i+1]; k-0e#"B
} o%Q2.
nEndPos[nEndPos.length-1] = nFileLength; RM$S|y{L
} scwlW b<N
} 0k]N%!U
4yy yXj
~,1X>N"
//启动子线程 kIo?<=F8T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]HT>-Ba;{h
for(int i=0;i<nStartPos.length;i++) o:ob1G[p%
{ KJZY.7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2mG?ve%m)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f2f$aZ
nStartPos,nEndPos,i); 13 p0w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h8;"B
fileSplitterFetch.start(); 36UWoo
} FQ^uX]<3j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,aL"Wy(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w=2X[V}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r${a S@F
nEndPos = " + nFileLength); |REU7?B
// fileSplitterFetch[nPos.length-1].start(); k Er7,c
m!if_Iq
vUA`V\
//等待子线程结束 yY|U}]u!V
//int count = 0; :g_ +{4
//是否结束while循环 -7Wmq[L/
boolean breakWhile = false; 1N*~\rV*?
<{j9|mt
e@YR/I8my
while(!bStop) =z.AQe+
{ 'KG`{K$
write_nPos(); V4D&&0&n
Utility.sleep(500); :{<HiJdp
breakWhile = true; ^jA}*YP
r&;AG@N/
~coG8r"o
for(int i=0;i<nStartPos.length;i++) euK!JZ
{ B[h9epU]K
if(!fileSplitterFetch.bDownOver) cFQa~
{ dno*Usx5d0
breakWhile = false; HN%ZN}
break; =r8(9:F!
} 54&2SU$kx
} Joj8'
if(breakWhile) /8R1$7
break; :=@[FXD4
l.! ~t1i
yE>DQ *
//count++; 8%B @[YDe
//if(count>4) ;2}Gqh)Yr
// siteStop(); TB\CSXb
} dl4.jLY
-TWo-iu^
5`Z#m:+u
System.err.println("文件下载结束！"); ;MD{p1w
} z=sqO'~
catch(Exception e){e.printStackTrace ();} 'M{_S
} Ws(>} qjy
h&{pMmS3,
BHYEd}M
//获得文件长度 ;.Y`T/eWS
public long getFileSize() ~qF9*{~!
{ _{aVm&^kA
int nFileLength = -1; @lI/g
try{ 9S^-qQH3}
URL url = new URL(siteInfoBean.getSSiteURL()); l=yO]a\QZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 60Z)AQs;+J
httpConnection.setRequestProperty("User-Agent","NetFox"); )_uK(UNZ5
H#D=vx'
O%I'
int responseCode=httpConnection.getResponseCode(); w;"'l]W
if(responseCode>=400) QX4I+x~oo\
{ &nYmVwi?"Q
processErrorCode(responseCode); V SxLBwXf
return -2; //-2 represent access is error +}n]A^&I\E
} D~Su822
tg:x}n
<tNx*ce5
String sHeader; aw`mB,5U
sC j3h
q b'ka+X
for(int i=1;;i++) ]pt @
{ Onl:eG;@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q. >"@c[
//Utility.log(in.readLine()); @S}'_g
sHeader=httpConnection.getHeaderFieldKey(i); 2r[,w]
if(sHeader!=null) = FQH
{ .Qaqkb-Ty
if(sHeader.equals("Content-Length")) 8LL);"$
{ ~(c<ioIf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0Z\fK>yw
break; lUrchLoDt
} 3yQ(,k#
} ,SBL~JJ
else 0y(d|;':
break; G100L}d"N
} k$zDofdfp
} ,70|I{,Km
catch(IOException e){e.printStackTrace ();} Y9C]-zEv
catch(Exception e){e.printStackTrace ();} k~H-:@
6^p6v
QeK~A@|F&
Utility.log(nFileLength); JS4pJe\q
6^~&sA
Uc&0>_Z
return nFileLength; CyE.q^Wm
} .{6TX"M
?#W>^Za=
J[9jNCq|
//保存下载信息（文件指针位置） u5lj+?
private void write_nPos() g\ke,r6
{ /];F4AO5
try{ .w0?
output = new DataOutputStream(new FileOutputStream(tmpFile)); =U:iR
output.writeInt(nStartPos.length); \"5\hX~dS
for(int i=0;i<nStartPos.length;i++) C'{Z?M>
{ HLS^Ga,(
// output.writeLong(nPos); 'h:4 Fzo<
output.writeLong(fileSplitterFetch.nStartPos); 7|2:;5:U
output.writeLong(fileSplitterFetch.nEndPos); 1vobfZ-w9
} HGPbx$!
output.close(); X'0A"9
} Bq'hk<ns[
catch(IOException e){e.printStackTrace ();} L,R9jMx?_
catch(Exception e){e.printStackTrace ();} YyI|^f8C
} /6>2,S8Ar
l9n8v\8,o
BV<LIrAS
//读取保存的下载信息（文件指针位置） *G=n${'
private void read_nPos() wTOB'
{ sO6+L #!
try{ %F03cI,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iK)w3S}k1y
int nCount = input.readInt(); 1y 6H2
nStartPos = new long[nCount]; wLW!_D,/R
nEndPos = new long[nCount]; ,5<-\"{]
for(int i=0;i<nStartPos.length;i++) Qg3 -%i/@
{ O9!<L.X,%
nStartPos = input.readLong(); 55hJRm3
nEndPos = input.readLong(); ?onZ:s2
} z]tvy).
input.close(); +&JF|#FQ`
} Ff|?<\x0}A
catch(IOException e){e.printStackTrace ();} ~aBALD0D;
catch(Exception e){e.printStackTrace ();} sjztT<{Q^-
} W/fM0=!
&bTadd%0
ZQ@^(64
private void processErrorCode(int nErrorCode) F+9|D
{ >&p_G0-
System.err.println("Error Code : " + nErrorCode); ;5oY)1
} -Ndd6O[ a5
?9/%K45
@aI`ru+a
//停止文件下载 AM\`v'I*6
public void siteStop() [S'ngQ"f`
{ }(ot IqE
bStop = true; d[jxU/.p;
for(int i=0;i<nStartPos.length;i++) C#;}U51:t
fileSplitterFetch.splitterStop(); GN(PH/fO9
z;1yZ4[G
_^Rf*G!
} J/=b1{d"n
} ;p)gTQa
//负责部分文件的抓取 ASPfzW2
**FileSplitterFetch.java 2#ypM9
*/ Iy\K&)5?
package NetFox; !%sj-RMvG
^+!!:J|ra
jg' 'T1)
import java.io.*; cy%^P^M
import java.net.*; .z)&#2E
-&%#R_RV
& Z*&&
public class FileSplitterFetch extends Thread { 3<#4
"m(HQ5e)*
nTp?
String sURL; //File URL R8?Xz5
long nStartPos; //File Snippet Start Position rWAJL9M
long nEndPos; //File Snippet End Position ,,lrF.
int nThreadID; //Thread's ID V]<J^m8
boolean bDownOver = false; //Downing is over 7l%O:M(\
boolean bStop = false; //Stop identical ' !ZFK}
FileAccessI fileAccessI = null; //File Access interface AI/xOd!a
?HAWw'QW
szGp<xv_p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6xvyhg#B
{ _.yBX\tf[
this.sURL = sURL; 8?J\
this.nStartPos = nStart; Q3'\Vj,S&
this.nEndPos = nEnd; `pOiv&>
nThreadID = id; S3A OT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ="JLUq*]s
} ldO6W7G|h
~;9B\fE`
H<Ed"-n$I<
public void run() u#ag|b/C:
{ oX8e}
while(nStartPos < nEndPos && !bStop) cEhwv0f!qS
{ ?1JS*LQ$
,=.&
VMe~aUd
try{ ?L|m:A`
URL url = new URL(sURL); LSs!U 3"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :?O+EE
httpConnection.setRequestProperty("User-Agent","NetFox"); @Q 8E)k@
String sProperty = "bytes="+nStartPos+"-"; [f!sBJ!
httpConnection.setRequestProperty("RANGE",sProperty); ]SA]{id+
Utility.log(sProperty); 0V}knR.l
^0Cr-
{|9x*I
InputStream input = httpConnection.getInputStream(); MDM/~Qpj_
//logResponseHead(httpConnection); Hw-,sze j"
rd vq(\A
h%|Jkx!v-t
byte[] b = new byte[1024]; )#%k/4(Y
int nRead; WyF1Fw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TyI"fP
{ o4^rE<vJ
nStartPos += fileAccessI.write(b,0,nRead); FZ)_WaqGf
//if(nThreadID == 1) dj3}Tjt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y&6vTU
} *fQ$s
!yI , ~`Z
G|*^W;(Z
Utility.log("Thread " + nThreadID + " is over!"); mR\rK&'6
bDownOver = true; {9S=:
//nPos = fileAccessI.write (b,0,nRead); QVA)&k'T,
} zUF%`CR
catch(Exception e){e.printStackTrace ();} $[x2L s~
} ,HO~NqmB4
} ]@wee08
|]kcgLqj
v1*Lf/
//打印回应的头信息 )u)]#z
public void logResponseHead(HttpURLConnection con) bKRz=$P?
{ //9Ro"
for(int i=1;;i++) ?=}~]A5N
{ #+I)<a7\
String header=con.getHeaderFieldKey(i); >1 {V
if(header!=null) ~"6/OJA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TY6 D.ikA
Utility.log(header+" : "+con.getHeaderField(header)); >G(M&
else c((^l&
break; )L fXb9}
} ~?T*D*
} kqxX!
zX*+J"x
XaOq&7
public void splitterStop() gb:)t}|
{ cyu)YxT
bStop = true; .hd<,\nW
} s wgn( -
f-!t31?XK
j{PuZ^v1
} & c a-
?|Y/&/;%I
K.'II9-{
/* J}a 8N.S
**FileAccess.java \@6PA
*//文件访问(定位，写) I`"B<=zi
package NetFox; KFd !wZ@e
import java.io.*; 0`y;[qAG[
?+EN.P[;3
Byq4PX%B
public class FileAccessI implements Serializable{ /4w"akB|P
pI*/-!I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l'h[wwEXm{
RandomAccessFile oSavedFile; E07g^y"}i
long nPos; %{'hpT~h
5T]GyftFV
'U=D6X%V9m
public FileAccessI() throws IOException 0{u31#0j
{ *oR`l32O0z
this("",0); -UgD
} :i'jQ<|wZN
qgTN %%"~
B1\@ n$
public FileAccessI(String sName,long nPos) throws IOException 38(Cj~u=3
{ Sg$14B
oSavedFile = new RandomAccessFile(sName,"rw"); zQsu~8PX
this.nPos = nPos; 'J*)o<%
oSavedFile.seek(nPos); mMLxT3Ci8
} nFE0y3GD8
L\p@1N?K
e>"/Uii
public synchronized int write(byte[] b,int nStart,int nLen) Nc4e,>$]&
{ z>_jC+
int n = -1; 6OeRBD&
try{ |cZKj|0>
oSavedFile.write(b,nStart,nLen); [p3)C<;ZC
n = nLen; "f'pa&oHi
} jU K0?S>
catch(IOException e) 40VdT|n$$
{ 9r@T"$V#c
e.printStackTrace (); E2f9J{Ki=
} ]A*v\Qy
Iz;hje4JL
t-#Y6U}b+
return n; [3":7bB 'E
} K%TlBKV
"],amJ
+bnz%/v
} wr\d5j
T?=[6
CfFNk "0{
/* |Tz/9t
**SiteInfoBean.java u#tLY/KA
*/ 'IrwlS
package NetFox; 7.O1 ~-
YE#OAfj~
}^J&D=J5V
public class SiteInfoBean { y@!kp*0
@=jcdn!\M
#^IEQZgH
private String sSiteURL; //Site's URL /?b<}am
private String sFilePath; //Saved File's Path $~,]F
private String sFileName; //Saved File's Name BS}uv3
private int nSplitter; //Count of Splited Downloading File a^+b(&;k
|qra.\
oL' :07_
public SiteInfoBean() 5p&&EA/
{//nSplitter的缺省值为5 *GsrG*OM*D
//default value of nSplitter is 5 n*\AB=|X
this("","","",5); yQQ[_1$pq
} |q$br-0+
/wIev1Z!Y
% ~%>3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B8'(3&)My
{ #mqz*=L3
sSiteURL= sURL; )F;[
sFilePath = sPath; fT.5@RR7^
sFileName = sName; GXaCH))TO
this.nSplitter = nSpiltter; 9\W~5J<7
i>bFQ1Rdx
S\<]|tM:x
} i3k ',8
%^RlE@l9
1 sCF -r
public String getSSiteURL() [.P~-6~
{ Rkfr4
return sSiteURL; kKVq,41'
} Py 8o8*H
vO" $Xw
cXcn}gKV
public void setSSiteURL(String value) ~AuvB4xe~
{ hIa@JEIt
sSiteURL = value; 9;;1 "^4/
} FK!9to>
AiiOs?
EAFKf*K=
public String getSFilePath() z$p+l]
{ }/G~"&N[
return sFilePath; ja2LQe@Q
} PpN+q:(
NW=j>7
9a)D8
public void setSFilePath(String value) (JFa
{ cd}TDd(H%
sFilePath = value; J.":oD
} j^ZpBNL
K@*m6)
B!<{s'
public String getSFileName() N|q:wyS|
{ |6\ ?"#
return sFileName; DC*|tHl
} vE?qF9I{$0
Y_PCL9G{p
I}Q3B3Byg
public void setSFileName(String value) }W<]fK
{ #eE:hiu<v
sFileName = value; 4$.UVW\
} )." zBc#
[.z1
LEVNywk[
public int getNSplitter() & A9psc(,&
{ V6wYJ$]
return nSplitter; ~2A<fL,-
} WP^%[?S2
$.kIB+K
biGaP#"0
public void setNSplitter(int nCount) )#3,y6
{ f{ S)wE>;
nSplitter = nCount; v}[KVwse
} 8qBRO[
} #_7}O0?c3
>1s:F5u"
B5B'H3@
/* @uY%;%Pa8
**Utility.java `-ENKr]
*/ .:RoD?px
package NetFox; "@`mPe/
#FaR?L![Y
QS=n 50T,
public class Utility { `!m+g0
V^L;Nw5h
#C%<g:F8
public Utility() L1)?5D
{ ~,':PUkiV
E C7f
m U7Ad"
} T_AZCl4d
{!oO>t
//线程睡眠 9zO;sg;3
public static void sleep(int nSecond) _,Fwt
{ mH?^3T
try{ =Z-.4\3
Thread.sleep(nSecond); >+oQxml6nI
} k )){1O
catch(Exception e) &Vgjd>
{ T/S-}|fhQ
e.printStackTrace (); :^iR&`2~
} OgHWmb
} yMz@-B
e`}|*^-
//日志 8CEy#%7]}
public static void log(String sMsg) cW&OVNj
{ 5&94VQ$d
System.err.println(sMsg); yx/:<^"-$
} l^0 <a<P
p3^7Hr
]Dx?HBM"DC
public static void log(int sMsg) &]z2=\^e
{ u%*;gu"2
System.err.println(sMsg); /[EI0~P
} M6?Qw=
} 9@vY(k k
,9+@\
(\R"v^
/* AH#e>kU^
**TestMethod.java OH=Ffy F,
*/ t9P` nfY
package NetFox; $<33E e:a
2EE#60
I|R9@
public class TestMethod { TD3R/NP
J::SFu=
[9+M/O|Vs
public TestMethod() i!,>3
{ ///xx/weblogic60b2_win.exe Uw)K[T
try{ n!tCz<v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lXz<jt@5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u8[X\f
SiteFileFetch fileFetch = new SiteFileFetch(bean); }:hdAZ+z
fileFetch.start(); Pel3e ~?t
} z-,U(0 .
catch(Exception e){e.printStackTrace ();} fk",YtS*
Bq$bxuhV
X$st{@}ZB
} wL%>
v1)jZ.:
}QC:!e,yG
public static void main(String[] args) E26ZVFg
{ ^|gN?:fA}
new TestMethod(); ="I]D I
} f8uVk|a
} g\jdR_/
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