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)); 4Gc M
} #z*,CU#S9d
for(int i=0;i<nEndPos.length-1;i++) H_DCdUgC'
{ 1 em,/>"
nEndPos = nStartPos[i+1]; za>UE,?h
} t]yxLl\
nEndPos[nEndPos.length-1] = nFileLength; tE7jTe
} m&UP@hUV-
} zM9#1^X
H U|.5tP
,fkvvM{mq
//启动子线程 5)k8(kH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uN|A}/hr]
for(int i=0;i<nStartPos.length;i++) _pvB$&
{ rbw$=bX}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )g0lI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `fu_){
nStartPos,nEndPos,i); @I_cwUO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I{Zb/}k-
fileSplitterFetch.start(); RLmOg{L
} WE<?y_0y&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N9e'jM>Oos
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !#tVQ2O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &`"DG$N(
nEndPos = " + nFileLength); $*yYmF
// fileSplitterFetch[nPos.length-1].start(); diq}\'f
D'" T'@
BuJo W@)
//等待子线程结束 $ V^gFes
//int count = 0; p@m0Oi,=
//是否结束while循环 z:Ml;y
boolean breakWhile = false; qpjY &3SI
1Ms[$$b$
/k#-OXP~
while(!bStop) g9_zkGc7
{ dGIdSQ~ _
write_nPos(); Rn1oD3w
Utility.sleep(500); OxlA)$.hpu
breakWhile = true; '%N?r,x C
Pf*6/7S:
b/SBQ"B%
for(int i=0;i<nStartPos.length;i++) jkAjYR.
{ m5\T,
if(!fileSplitterFetch.bDownOver) hnnB4]c
{ 0Y.z
breakWhile = false; U&!TA(Yr
break; j#NyNv(jE1
} =$>=EBH,cm
} `+7F H
if(breakWhile) 615Ya<3f8
break; ,6)N.
ks405
xEb>6+-F@
//count++; #8$?# dT
//if(count>4) Y"Cf84E
// siteStop(); ZlT }cA/n
} pu-HEv}]a|
eV;r /4
_:x]'w%
System.err.println("文件下载结束！"); 9^gYy&+>6]
} E C?}iP
catch(Exception e){e.printStackTrace ();} Ss3p6%V/
} ^QK`z@B
=7Ln&tZ
}0'=}BE
//获得文件长度 xQoZ[
public long getFileSize() u?osX;'w
{ L\:|95Yq
int nFileLength = -1; H4$qM_N
try{ 'o AmA=
URL url = new URL(siteInfoBean.getSSiteURL()); !8{VLg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Oyo /?/
httpConnection.setRequestProperty("User-Agent","NetFox"); sS D8Sx/
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@Jt$92i5PS
int responseCode=httpConnection.getResponseCode(); -JW~_Q[
if(responseCode>=400) ]\E"oZ
{ lZFu|(
processErrorCode(responseCode); Q@D7\<t
return -2; //-2 represent access is error VtBC~?2U)B
} &D,Iwq
d?,'$$aB
{ 3G
String sHeader; v 6~9)\!j
agIqca;
DUp`zW;B
for(int i=1;;i++) p{f R$-d
{ HJL! ;i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y:^hd809
//Utility.log(in.readLine()); Hon2;-:]{]
sHeader=httpConnection.getHeaderFieldKey(i); -Q WvB
if(sHeader!=null) !09)WtsEfx
{ 144Y.
if(sHeader.equals("Content-Length")) AdX))xgl
{ OO:S2-]Y>e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uLhGp@Dx
break; Od1\$\4Z
} q_MN
} \PrJy6&
else iw@rW5%'~
break; Q(|@&83].
} A8{jEJ=)P
} rRTKF0+
catch(IOException e){e.printStackTrace ();} |IgR1kp+.
catch(Exception e){e.printStackTrace ();} Xp<q`w0I,
"1O_h6C
n,N->t$i
Utility.log(nFileLength); i3-5~@M
2)}n"ibbT
Q*DT" W/0
return nFileLength; m\:^9A4HCg
} V!}I$JiJ
]RVu[k8
r,5e/X
//保存下载信息（文件指针位置） -@v^. @[Z&
private void write_nPos() iZGbNN
{ Lg:1zC
try{ Wu>]R'C
output = new DataOutputStream(new FileOutputStream(tmpFile)); eG=d)`.JaV
output.writeInt(nStartPos.length); P1#g{f
for(int i=0;i<nStartPos.length;i++) 5Xq+lLW>
{ 2/-m-5A
// output.writeLong(nPos); B=SA +{o
output.writeLong(fileSplitterFetch.nStartPos); corm'AJ/
output.writeLong(fileSplitterFetch.nEndPos); Ly=.
} A95f!a
output.close(); Xdvd\H=
} :;$MUOps
catch(IOException e){e.printStackTrace ();} E-A9lJWr
catch(Exception e){e.printStackTrace ();} inu.U[.
} HQ-[k$d W4
wL;OQhI
lrrTeE*
//读取保存的下载信息（文件指针位置） *G"hjc$L
private void read_nPos() X3:1KDVsV
{ }7PJr/IuF
try{ ;,y_^-h;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1+%UZK= K
int nCount = input.readInt(); .k#PrT1C
nStartPos = new long[nCount]; y?sz&*:
nEndPos = new long[nCount]; ZCCCuB
for(int i=0;i<nStartPos.length;i++) \XDiw~0
{ \f,<\mJ#
nStartPos = input.readLong(); ?1Nz ,Lc$
nEndPos = input.readLong(); kQ\GVI11?
} ]TvMT
input.close(); x[A|@\Z
} 757&bH|a
catch(IOException e){e.printStackTrace ();} +17!v_4^
catch(Exception e){e.printStackTrace ();} .Xlo-gHk
} |nMjv]#
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G|cjI*
private void processErrorCode(int nErrorCode) ,Yag! i>;
{ RDps{),E;d
System.err.println("Error Code : " + nErrorCode); k>i88^kPV
} Fe8X@63
3M#x)cW
bTs2$81[
//停止文件下载 HT7,B(.}
public void siteStop() 1wgL^Qz@
{ ydWr&E5
bStop = true; GRc)3 2,
for(int i=0;i<nStartPos.length;i++) GMU!GSY
fileSplitterFetch.splitterStop(); \`.v8C>vG
l;M,=ctB(
Zma;An6
} tP_.-//
} r] /Ej!|
//负责部分文件的抓取 f2.=1)u.
**FileSplitterFetch.java 7mtx^
*/ "P7OD^(x/
package NetFox; >s<Bu'r
N8]DzE0%
9KK^1<46c
import java.io.*; RHsVG &<j
import java.net.*; D#nHg
@(R=4LL
g0f4>m
public class FileSplitterFetch extends Thread { l!1_~!{y
6AIqoX*p
uh\G6s!4/
String sURL; //File URL 5K Ij}VN
long nStartPos; //File Snippet Start Position ^"Bhp:o2
long nEndPos; //File Snippet End Position BOpZ8p'eH1
int nThreadID; //Thread's ID :ok.[q
boolean bDownOver = false; //Downing is over Y`gO:d8
boolean bStop = false; //Stop identical Q8m~L1//S
FileAccessI fileAccessI = null; //File Access interface Mg >%EH/'
P`rfDQoZ
&D<6Go/)_*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >p&"X 2 @
{ VjM/'V5
this.sURL = sURL; JCH9~n.
this.nStartPos = nStart; rDl/R^w"
this.nEndPos = nEnd; #x 6/"Y2
nThreadID = id; Up Z 9g"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hUpour |b
} (~Z&U
[kJ;Uxncz~
iKq_s5|sW
public void run() (ot,CpI(I
{ "%K'~"S#Q,
while(nStartPos < nEndPos && !bStop) H~*N:$C
{ F=5+JjrX
)]n>.ZmLCB
gpq ,rOIK
try{ o^@#pU <
URL url = new URL(sURL); KXZG42w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LYAGpcG
httpConnection.setRequestProperty("User-Agent","NetFox"); <hzHrx'o{
String sProperty = "bytes="+nStartPos+"-"; Cuylozj$&
httpConnection.setRequestProperty("RANGE",sProperty); Dx\~#$S!=
Utility.log(sProperty); f0eQq;D$K
PE.UNo>o
S))B^).0-
InputStream input = httpConnection.getInputStream(); *vQ 6LF;y
//logResponseHead(httpConnection); rvx2{1}I
`;Ui6{|
'!$QI@@
byte[] b = new byte[1024]; =nHkFi@D=t
int nRead; p$F`9_bZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :@p]~{m:G
{ F=&,=r'Q8
nStartPos += fileAccessI.write(b,0,nRead); v1u~[c=|^
//if(nThreadID == 1) H-t$A, [
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0~<?*{~
} h0-.9ym
G%Lt>5*!nE
TFldYKd/l
Utility.log("Thread " + nThreadID + " is over!"); ~M7X]
bDownOver = true; EFiVwH
//nPos = fileAccessI.write (b,0,nRead); $Ptl&0MN%
} {pQ8/Af!
catch(Exception e){e.printStackTrace ();} C{U*{0}
} '`tFZfT
} ty[%:eG#
Ud"_[JtGM
<|'ETqP<+
//打印回应的头信息 mR2"dq;U
public void logResponseHead(HttpURLConnection con) #Br`;hL<T
{ ZYB5s~;eB"
for(int i=1;;i++) Gy+c/gK
{ f2tCB1[D+
String header=con.getHeaderFieldKey(i); +%<kcc3
if(header!=null) ZK?V{X{";
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |5(CzXR]
Utility.log(header+" : "+con.getHeaderField(header)); Lww&[|k.
else ,aWI&ve6
break; %-YWn`yEm
} t.&JPTK-H
} ZT"vVX-)G
Ag3+z+uS
LD{~6RP
public void splitterStop() `4ga~Ch
{ [6\O <-?
bStop = true; Li8/GoJW-T
} fx:vhEX
U4Zx1ieCKH
HI1|~hOb'
} MF$Dx| Tcj
'oGMr=gp<&
a^G>|+8
/* ">B&dNrt
**FileAccess.java s o: o b}
*//文件访问(定位，写) }.u[';q]S
package NetFox; gdAd7 T
import java.io.*; .R)Ho4CE
jn]l!nm
xn=mS!"1Zo
public class FileAccessI implements Serializable{ @Nm{H
gjiS+N[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EGRIhnED#
RandomAccessFile oSavedFile; @<OsTF L
long nPos; -0'<7FSQ
od@!WjcM[8
R0w~ Z
public FileAccessI() throws IOException *?Oh%.HgF
{ Mu.tq~b >
this("",0); 8u*Q^-fpo0
} 'mv|6Y
_x-2tnIxXv
)+)qFGVz
public FileAccessI(String sName,long nPos) throws IOException ~urk Uz
{ #p{8
oSavedFile = new RandomAccessFile(sName,"rw"); 1@-l@ P
this.nPos = nPos; nbw8YO(=
oSavedFile.seek(nPos); wd,6/5=lh
} 2#R0Bd
/ H GPy
Qm[ )[M
public synchronized int write(byte[] b,int nStart,int nLen) p-oEoA
{ %h_N%B$7c1
int n = -1; D1]?f`
try{ .i7"qq.M
oSavedFile.write(b,nStart,nLen); ;M+~e~
n = nLen; Q>z(!'dw
} -hK^*vJ
catch(IOException e) ) [)1
{ SQ/}K8uZ
e.printStackTrace (); R{B5{~m>W@
} U~|)=+%O
W9GjUswv!
3;//o<
return n; P=ubCS'
} j;_E0j#
`y"a>gHC
3!KyO)8
} Ngrj@_J
S>[&]
W Emh
/* JFRbWQ0
**SiteInfoBean.java U d+6=Us{
*/ U,<?]h
package NetFox; DI :
`'rvDaP
Fe2iG-ec
public class SiteInfoBean { 8P%Jky&(
EBmkKiI;
L$]Y$yv
private String sSiteURL; //Site's URL w~AO;X*Ke"
private String sFilePath; //Saved File's Path JWQd6JQ_~V
private String sFileName; //Saved File's Name yTWicW7i
private int nSplitter; //Count of Splited Downloading File j3o?B
_bCIVf`
4?`*#DPl
public SiteInfoBean() @Y%i`}T%(
{//nSplitter的缺省值为5 ;A?86o'?
//default value of nSplitter is 5 :9|CpC`.
this("","","",5); L3S29-T
} C61E=$
|kHzp^S
X-yS9E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fHF*#
{ C9%A?'`
sSiteURL= sURL; G Mg|#DV
sFilePath = sPath; 5N#Sic M
sFileName = sName; (]"`>,ray
this.nSplitter = nSpiltter; vf!lhV-UG+
YQ-V^e6
ocj^mxh=O
} tY`%vI [
ZjgfkZAS
r#mH[|@W~
public String getSSiteURL() G'iE`4`2
{ #!jwn^yq
return sSiteURL; a/~1CrYr
} _o6Zj1p
ib(4Y%U6~
aslb^
public void setSSiteURL(String value) ~kZ?e1H
{ a^)@}4
sSiteURL = value; ZGS4P0$
} c*V/2" 5
Q/l388'
239gpf]}
public String getSFilePath() d?[8VfAnh
{ )%I62<N,z
return sFilePath; 1[(/{CClB
} \2[
_WBWFGj
0w".o!2\U{
public void setSFilePath(String value) {G-y7y+E
{ Z"9D1Uk
sFilePath = value; Oz5Ze/HBN
} YZc{\~d
1{CVd m<9
nhB.>ReAi
public String getSFileName() P\2x9T
{ N}\3UHtO
return sFileName; X> V`)
} 5eX+9niY
M^y5 Dep
1v9#Fr Y
public void setSFileName(String value) <)$JA
{ 4#D>]AX
sFileName = value; Z7=k$e
} |EP=<-|
QqB9I-_
!@f!4n.e|I
public int getNSplitter() M~*o =t
{ Y#oY'S .;y
return nSplitter; L@~0`z:>iP
} #D Oui]
M~djX} #\
jGKI|v4U(
public void setNSplitter(int nCount) ;<s0~B#9}
{ joJQ?lG
nSplitter = nCount; Ft 2u&Rtx
} C<q@C!A
} (x8D ]a
$&FeR*$|g
MMyJAGh ^G
/* \r&9PkHWo
**Utility.java Ehg(xK
*/ i/q1>
package NetFox; R?J=5tO
`>\>'V<&
@HP7$U"
public class Utility { $McbVn)~f
@<=<?T>1
0`kaT ?>
public Utility() .Za)S5U
{ +r 8/\'u-
?&$BQK
hdy N
} -e_L2<7
Mzj|57:gx
//线程睡眠 "S0WFP\P+
public static void sleep(int nSecond) Tf.DFfV#y
{ K`twbTU
try{ FSkz[D_}
Thread.sleep(nSecond); McRfEF\
} ~|=goHmm[
catch(Exception e) @x/D8HK2
{ L%0G >2x
e.printStackTrace (); Hge0$6l
} hH=}<@z
} qku!Mg
{Nny.@P)H
//日志 7\ kixfEg
public static void log(String sMsg) gwv s
{ Y #6G&)M
System.err.println(sMsg); vC%8-;8{H
} N&-J,p~
hBNA,e:
}:4b_-&Q5
public static void log(int sMsg) ^n<o,K4\}
{ T8-,t];i
System.err.println(sMsg); TCetd#;R
} K_CE.8G&{
} iCh,7I,m
6@geakq
K_[B@( Xl
/* 5!iBKOl#D
**TestMethod.java J(=io_\bO
*/ <%:,{u6
package NetFox; h4k.1yH;
rnS&^
\"?5CHz*
public class TestMethod { Z-rHYfa4
TAKvE=a;
hScC<=W
public TestMethod() .{ r %C4q9
{ ///xx/weblogic60b2_win.exe @_C?M5v
try{ *MZa|Xy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pn-`QB:{h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8;1,saA_9
SiteFileFetch fileFetch = new SiteFileFetch(bean); !t!\b9=
fileFetch.start(); b[`fQv$G
} /zZ";4
catch(Exception e){e.printStackTrace ();} O}mz@-Z
7':qx}c#!1
db5@+_
} )|`|Usn#[
HMPb%'U~
DNy 6Kw
public static void main(String[] args) 8AuOe7D9A
{ Q,<V)
new TestMethod(); VVDd39q
} e)A-.SRiO$
} 0`%Ask
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