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)); 1bb~u/jU
} H"W%+{AR
for(int i=0;i<nEndPos.length-1;i++) $FEG0&
{ CK1Xdyf_S
nEndPos = nStartPos[i+1]; 6y&d\_?Y
} (9x8,f0z
nEndPos[nEndPos.length-1] = nFileLength; CW>f;
} ,mH2S/<}S
} ]Lq9Ompf(t
cCN[c)[c|
YK#bzu ,!
//启动子线程 }?xu/C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (v*$ExF
for(int i=0;i<nStartPos.length;i++) 9,y*kC
{ #"%=7(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _A%} >:q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R*I{?+
nStartPos,nEndPos,i); `i0RLGze
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '7}s25[{\
fileSplitterFetch.start(); z8+3/jLN0B
} 3X,9K23T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xfw)0S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ('!90
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &G?b|Tb2
nEndPos = " + nFileLength); ?1 $.^
// fileSplitterFetch[nPos.length-1].start(); @qH{;
A<.`HCv2
0hK)/!Y
//等待子线程结束 s<x2*yVUA
//int count = 0; ?}y?e}y*xZ
//是否结束while循环 uNV(r"
boolean breakWhile = false; ipfiarT~)
\:C@L&3[
`V[{(&?,n
while(!bStop) +~RiCZt
{ b8v?@s~
write_nPos(); jI0gQ [
Utility.sleep(500); B@dA?w.x
breakWhile = true; p;Kw$fQ?
:~BY[")
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for(int i=0;i<nStartPos.length;i++) dC;@ Fn
{ E`.dU<8HE
if(!fileSplitterFetch.bDownOver) Hw[u Sv8
{ ,dK<2XP
breakWhile = false; y)?Sn
break; g9I2 e<;o
} ZZp6@@zyq'
} !Y/$I?13Z
if(breakWhile) !q!.OQ
break; =rcqYPul0
O#fGHI<43[
X2!vC!4P?L
//count++; 5F$ elW
//if(count>4) # (B <n
// siteStop(); GQO}E@W6C
} .0;Z:x_3
MHJH@$|]
~7T]l1]W%
System.err.println("文件下载结束！"); VqLqj$P
} ;_)&#X,?(
catch(Exception e){e.printStackTrace ();} LDHuf<`
} B'B,,Mz
FS30RP3 `/
<zH24[
//获得文件长度 fQq'_q5
public long getFileSize() DQY*0\
{ u-0-~TwD
int nFileLength = -1; !\.x7N<)0
try{ *j RNpB{)z
URL url = new URL(siteInfoBean.getSSiteURL()); 7*]O]6rP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?n9gqwO
httpConnection.setRequestProperty("User-Agent","NetFox"); Qc-jOl
'ek7e.x|V
oVyOiWo\Z
int responseCode=httpConnection.getResponseCode(); Z?Y14L~%
if(responseCode>=400) B/g.bh~)q
{ wYK-YY:Q3
processErrorCode(responseCode); !8M]n
return -2; //-2 represent access is error smW 7zGE
} V9f$zjpw
.4pWyqU)!
|T0jq
String sHeader; ZAVjq;bq
Nw'i;}0v7r
e*.l6H/B
for(int i=1;;i++) 6VpT*,2d~
{ GV'Y'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <eKF
//Utility.log(in.readLine()); chW 1UE
sHeader=httpConnection.getHeaderFieldKey(i); y`!~JL*
if(sHeader!=null) =b2/g[
{ #Q}`kFB`
if(sHeader.equals("Content-Length")) 4% )I[-sH
{ -R@mnG 5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #x!h BS!
break; rAq2
} p5&:>>
} +m kub}<a
else (mIw3d8Tz
break; AdDlS~\?
} 'H-: >'k
} CEjMHP$=
catch(IOException e){e.printStackTrace ();} fvgjqiT
catch(Exception e){e.printStackTrace ();} Mq;m+{B
5SKj% %B2,
`+cc{k
Utility.log(nFileLength); :G\f(2@
hOjy$Z
yUcWX bT@
return nFileLength; Cc7PhoPK
} ~YO99PP
r=lhYn
3:1 h:Yc<
//保存下载信息（文件指针位置） Xi`K`Cu+
private void write_nPos() [h20y
{ 9BgR@b
try{ QQ^P IQj
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]Z%9l(
output.writeInt(nStartPos.length); -:]_DbF
for(int i=0;i<nStartPos.length;i++) ~LqjWU
{ v8Gm;~
// output.writeLong(nPos); BMMWP
output.writeLong(fileSplitterFetch.nStartPos); ?v?b%hK!;
output.writeLong(fileSplitterFetch.nEndPos); ~_R8; b
} kX!TOlk3
output.close(); FYU)sQ
} R@_i$Df|
catch(IOException e){e.printStackTrace ();} c+P.o.k;
catch(Exception e){e.printStackTrace ();} K1]m:Y<
} (F9U`1~4
-)_"7}|u5
_GSl}\
//读取保存的下载信息（文件指针位置） KLi&TmIB
private void read_nPos() YJi C}.4Q
{ ]/>(C76
try{ H0tjBnu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~kM# lh7At
int nCount = input.readInt(); J_) .Hd
nStartPos = new long[nCount]; }: v&Nc
nEndPos = new long[nCount]; F"o K*s
for(int i=0;i<nStartPos.length;i++) I\eM8`Y$
{ ;G!JKg
nStartPos = input.readLong(); oqeA15k$
nEndPos = input.readLong(); CtiTXDc_
} $<&N#
input.close(); <2Q+? L{
} iOk^RDG+
catch(IOException e){e.printStackTrace ();} ;#a^M*e
catch(Exception e){e.printStackTrace ();} zyb>PEd.
} znm3b8ns
v%8.o%G
6Ap-J~4
private void processErrorCode(int nErrorCode) kOi@QLdN
{ +zMWIG
System.err.println("Error Code : " + nErrorCode); 8XFs)1s[
} q^5j&jx Vl
tB-0wD=PR
JRfG]u6GU
//停止文件下载 CHxu%-g
public void siteStop() ! *Snx
{ :5`=9_|
bStop = true; 7OSk0%Q,
for(int i=0;i<nStartPos.length;i++) T \d-r#{
fileSplitterFetch.splitterStop(); a B(_ZX'L
90ZMO7_
,ru2C_LQ
} Z{<&2*
} X)P;UVR0
//负责部分文件的抓取 [N]5)n
**FileSplitterFetch.java S3Q^K.e?
*/ `1;m:,9
package NetFox; @APv?>$)
Ll4/P[7:?
$H}G'LqiG
import java.io.*; QnHb*4<
import java.net.*; 4KH8dau.fF
.;),e#
`xb\)
public class FileSplitterFetch extends Thread { r57CyO
k'H+l]=
`v;9!ReZV
String sURL; //File URL ,ddoII
long nStartPos; //File Snippet Start Position ;h|zNx0
long nEndPos; //File Snippet End Position Yi?X|"\`
int nThreadID; //Thread's ID >J4Tk1//b
boolean bDownOver = false; //Downing is over M1UabqQ
boolean bStop = false; //Stop identical @D$^- S6
FileAccessI fileAccessI = null; //File Access interface 9@'^}c#
D}.Pk>5
)w3?o#@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =8`!Ph@(
{ _[J @w.l(
this.sURL = sURL; .K I6<k/
this.nStartPos = nStart; K+2sq+3q
this.nEndPos = nEnd; 0^l)9zE
nThreadID = id; 7sgK+ ip
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wlSl ~A/s
} zVeQKN9^Z
Xaz`L
)Q:.1Hgl
public void run() AcRrk
{ G3Z>,"w;=
while(nStartPos < nEndPos && !bStop) BC*)@=7fx
{ 4gyC?#Ede
j.}@9
|_fmbG
try{ O$ p
URL url = new URL(sURL); 'aj97b;lpG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mI$<+S1!
httpConnection.setRequestProperty("User-Agent","NetFox"); ,drbj.0-
String sProperty = "bytes="+nStartPos+"-"; g4p-$WyT8>
httpConnection.setRequestProperty("RANGE",sProperty); }02#[vg
Utility.log(sProperty); nw.,`M,N
H@-txO1`::
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InputStream input = httpConnection.getInputStream(); c%?31t
//logResponseHead(httpConnection); hU: 9zLe
`=}w(V8pc
.k_> BD];
byte[] b = new byte[1024]; Z{Si`GA
int nRead; SK6?;_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F},#%_4
{ Hj\iI p
nStartPos += fileAccessI.write(b,0,nRead); .N:& {$o:
//if(nThreadID == 1) ~OdE!!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [.ya&E)x
} #Qir%\*V
Ll2yJ .C4
q:iB}ch5R
Utility.log("Thread " + nThreadID + " is over!"); (SH<]@s
bDownOver = true; "#ctT-g`6
//nPos = fileAccessI.write (b,0,nRead); `]u!4pP"
} /"q wC
catch(Exception e){e.printStackTrace ();} AbqeZn
} pgp@Zw)r)k
} %1\MW+
"W"2Y(
\ytF@"7
//打印回应的头信息 F\K&$5J{p
public void logResponseHead(HttpURLConnection con) W{)RJ1
{ =qg;K'M5
for(int i=1;;i++) ?.*^#>-
{ k'(d$;Jgr
String header=con.getHeaderFieldKey(i); &"_5?7_N
if(header!=null) {jK:hQX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c3L)!]kB
Utility.log(header+" : "+con.getHeaderField(header)); @2X{e7+D
else o+}>E31a
break; o.o$dg(r!
} per$%;5E"
} k Q Sx65
R&vV!d
YA?46[:
public void splitterStop() $;k2b4u
{ 2#y-3y<G
bStop = true; F4b$
} (4GDh%
6g6BE^o\
hxT{!g
} OV.f+_LS
WP}NHz4H
$2><4~T;|A
/* btG+Ak+K*
**FileAccess.java #?3oGrS Y
*//文件访问(定位，写) ]cKxYX)J
package NetFox; '{-7%>`bn
import java.io.*; ntZl(]l
ru>c\X^|
l`mNOQ@}'
public class FileAccessI implements Serializable{ *vqr+jr9
0t^Tm0RzH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eBN!!Y:7
RandomAccessFile oSavedFile; ge[hAI2I
long nPos; h!zev~u1)`
ab!Cu8~v
i(9 5=t(
public FileAccessI() throws IOException n2p(@
{ Q7{/ T0
this("",0); 7_G$&
} mne?r3d
#X`qkW.T<
C1M @;
public FileAccessI(String sName,long nPos) throws IOException wG-lR,glb
{ `B%IHr
oSavedFile = new RandomAccessFile(sName,"rw"); a3wk#mH
this.nPos = nPos; lx H3a :gm
oSavedFile.seek(nPos); [S:{$4&
} ^C|N
@dHQ}Ni
]Jum(1Bo
public synchronized int write(byte[] b,int nStart,int nLen) R2Y.s^
{ -~rZ| W~v
int n = -1; 5 A2u|UU
try{ @ )2<$d
oSavedFile.write(b,nStart,nLen); "<Q,|Md
n = nLen; >u0B ~9_E
} qF? n&>YG
catch(IOException e) 6");NHE
{ ^77Q4"{W
e.printStackTrace (); Z'cL"n\9R]
} OH_mZA
7lH.>n
`JZ`j7f
return n; 6|@\\\l
} 1:j[p=Q&
VX+:C(m~
>S[NI<=8S
} 7,IH7l|G
C?h}n4\B^?
cxB{EH,2Um
/* |.~0Ulk,
**SiteInfoBean.java )1ct%rue
*/ \-Ipa59U
package NetFox; $%"?0S
2t3DQ
8w\ZY>d
public class SiteInfoBean { *f*o ,~8V1
\-nbV#{
1R"?X'w
private String sSiteURL; //Site's URL H]<@\g*l@P
private String sFilePath; //Saved File's Path @ rG=>??k
private String sFileName; //Saved File's Name @@pI>~#zh
private int nSplitter; //Count of Splited Downloading File =hq+9 R8=
~}@cSv'(1
^)i1b:4
public SiteInfoBean() B4kJ 7Pdny
{//nSplitter的缺省值为5 )ePQN~#K}
//default value of nSplitter is 5 lG/h[
this("","","",5); d>-k-X-[
} 0)HZ5^J
Gi7p`F.
LO@='}D=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CS\T@)@t
{ ^,sKj-
sSiteURL= sURL; '(-SuaH49
sFilePath = sPath; nm{J
sFileName = sName; ;+NU;f/WM
this.nSplitter = nSpiltter; fZNWJo# `.
%VsIg
(-bLP
} ? f>pKe
2J1YrHj3
G5hh$Nmpi
public String getSSiteURL() }Q#3\z5
{ -8pQI
return sSiteURL; dOx0'q"Z
} /^9KZj
.{-C*
N^@aO&+A
public void setSSiteURL(String value) \ QE?.Fx
{ t{g7 :A
sSiteURL = value; fKQq]&~ H
} Q3P*&6wA
>u/ T`$
<xO" E%t
public String getSFilePath() wu`P=-
{ 0$1-5XY9
return sFilePath; WJs2d73Qp
} ` Clh;
5fuB((fd(
|x$2-RUP
public void setSFilePath(String value) Qk#`e
{ Y!*F-v@
sFilePath = value; Fo$'*(i
} '@3Kq\/
T$vDw|KSVP
#*)X+*
public String getSFileName() :}{,u6\
{ @q<F_'7is
return sFileName; ffgb3
} #z&@f
ZMn~QU_5
(sN;B)
public void setSFileName(String value) 'rSP@
{ :I/i"g7<
sFileName = value; U%T{~f
} bS"zp6Di
rFl6xM;F
n[tES6u
public int getNSplitter() H;k-@J
{ 9S! 2r
return nSplitter; Di>B:=
} /+g)J0u
Lcow2 SbH
A{,ZfX;SPO
public void setNSplitter(int nCount) ,3p$Z
{ o@j)clf
nSplitter = nCount; +L>?kr[i[
} WB(Gx_o3
} \95O
Qs1e0LwA9
lq*{2M{[
/* EI!e0V1!
**Utility.java CF0i72ul5
*/ jp|1S^b
package NetFox; +u|p<z
SZ3UR
wbA<G&h~
public class Utility { ,'z=cB`+o
eR*y<K(d
Aat-938FP6
public Utility() #s]'2O
{ VY]L<4BfGL
Kh,zp{
1?hx/02
} %9Y3jB",2
dRu|*s
//线程睡眠 G ;fc8a[X
public static void sleep(int nSecond) 2Pz)vnV"
{ NU{`eM
try{ N"Mw1R4
Thread.sleep(nSecond); T]0H&Oov
} qG?svt
catch(Exception e) ),;O3:n
{ 8DO3L "
e.printStackTrace (); ;[R#:Rk
} %SJ2W>e
} 6&KvT2?tA`
hH])0C
//日志 &m8Z3+Ea
public static void log(String sMsg) sBV})8]KM
{ JrgpDZ
System.err.println(sMsg); @24)*d^1
} 9zs!rlzQ
ObIL w
w/UZ6fu
public static void log(int sMsg) J_ y+.p- 5
{ nBo?r}t4
System.err.println(sMsg); # @~HpqqR
} qr|v|Ejd~
} t~(|2nTO5
D/x!`&.sN
O\&[|sGY{
/* _oBJ'8R\
**TestMethod.java \Uh$%#}.
*/ GO<,zOqvU
package NetFox; "B"Yfg[
( {}Z '
p81Vt
public class TestMethod { 8{ooLdpX7
6(as.U>K
?Ja&LNI9S
public TestMethod() E Zh.*u@^r
{ ///xx/weblogic60b2_win.exe #BLmT-cl
try{ 75?z" i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2(5<Wj"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G>>TB{}
SiteFileFetch fileFetch = new SiteFileFetch(bean); &w7Ev21
fileFetch.start(); *Tyr
} 66 @#V
catch(Exception e){e.printStackTrace ();} r< ~pSj
'7;b+Vbl#
ZA{T0:
} _Cnl|'
b`yb{& ,?
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public static void main(String[] args) Fh0cOp(
{ U\~9YX8
new TestMethod(); 4_&+]S
} oTLA&dy@
} .m/$ku{/J
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