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)); tW>R 16zq
} B;r$( 'UZ
for(int i=0;i<nEndPos.length-1;i++) yFo5pKF.J
{ eHe /w9`$R
nEndPos = nStartPos[i+1]; `qz5rPyZ
} {eEWfMKIn
nEndPos[nEndPos.length-1] = nFileLength; GcCs}(eo
} _'U?!
} E;H(jVZ
dCTpO
P0z{R[KBH
//启动子线程 =[+&({
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5#\p>}[HG
for(int i=0;i<nStartPos.length;i++) u_8 22Z
{ NGUGN~p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AHY)#|/)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q?4uH;h:^G
nStartPos,nEndPos,i); A5ID I<a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uc0'XPo3I
fileSplitterFetch.start(); MlE~gCD
} h';v'"DoW`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e&4u^'+K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CD[=z)<z{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G\ZRNb
nEndPos = " + nFileLength); :q<%wLs
// fileSplitterFetch[nPos.length-1].start(); m4>oE|\
h_yR$H&tX
S(h*\we
//等待子线程结束 J)|K/W9
//int count = 0; Gx_e\fe-/
//是否结束while循环 b.*4RL
boolean breakWhile = false; @ -d4kg
\#,#_
j]O[I^5
while(!bStop) ix@rq#
{ RgA4@J#
write_nPos(); jgw'MpQm{
Utility.sleep(500); ]?$y}
breakWhile = true; N-YZ0/c
2{Iz
^X%4@,AE
for(int i=0;i<nStartPos.length;i++) d}cJ5!d
{ ldvxYq<:
if(!fileSplitterFetch.bDownOver) K0=E4>z,`q
{ Jjh!/pWZ4
breakWhile = false; vXQmEIm
break; <# r.}T.l
} 7h/Q;P5
} 0]W]#X4A
if(breakWhile) +STzG/9#
break; 72vGfT2HtZ
=e-aZ0P
x>"JWD
//count++; -L?% o_
//if(count>4) 8z8SwWS?
// siteStop(); .OS?^\
} )}\@BtcjA]
)ZyuF(C&
!>Y\&zA
System.err.println("文件下载结束！"); ]mo<qWRc>p
} Rha3
catch(Exception e){e.printStackTrace ();} !&jgcw/E
} S&]<;N_B
oe|<xWu
x0$:"68PW
//获得文件长度 ~LW%lMy;^|
public long getFileSize() NZW)X[nXM
{ :42;c:85
int nFileLength = -1; Mqf}Aiqk;
try{ SH$cn,3F8
URL url = new URL(siteInfoBean.getSSiteURL()); `oRs-,d|<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8yz((?LrDh
httpConnection.setRequestProperty("User-Agent","NetFox"); &|"I0|tJ
'!h0![OH
h]DECd{
int responseCode=httpConnection.getResponseCode(); xYVjUb(,X
if(responseCode>=400) D4]B>
{ 4U;XqUY /
processErrorCode(responseCode); [pFu ]^X
return -2; //-2 represent access is error xp8f
} seU^IC<
'Qq_Xn8
SJc@iffS
String sHeader; bok 74U]
jy@i(@Z
"mK i$FV
for(int i=1;;i++) o``>sBZOq
{ /A))"D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rjQhU%zv
//Utility.log(in.readLine()); +ls*//R
sHeader=httpConnection.getHeaderFieldKey(i); :tqm2t
if(sHeader!=null) x`6^+>y^
{ Sc$8tLDLj
if(sHeader.equals("Content-Length")) -@V"i~g<e
{ FO>(QLlH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mS~ ]I$
break; UK_aqB
} DcR}pQ(e
} 5h=TV
else <6O_t,K]
break; >aC\_Mc
} kxqc6
} r{2].31'
catch(IOException e){e.printStackTrace ();} V52C,]qQH
catch(Exception e){e.printStackTrace ();} l8AEEG8>
ZIL| .<8I
n$|c{2]=
Utility.log(nFileLength); zvb}p
9C)3 b3
/b:t;0G
return nFileLength; i|]Va44
} =Pb5b6Y@6
5-WRv;
[aM'
//保存下载信息（文件指针位置） 3AQ>>)T~
private void write_nPos() C| L^Ds0
{ $7DcQ b9
try{ $n#Bi.A j
output = new DataOutputStream(new FileOutputStream(tmpFile)); %::deV7
output.writeInt(nStartPos.length); dbuJ~?D,
for(int i=0;i<nStartPos.length;i++) 6+B{4OY
{ "$IXZ
// output.writeLong(nPos); =i^<a7M~
output.writeLong(fileSplitterFetch.nStartPos); 4,F3@m:<
output.writeLong(fileSplitterFetch.nEndPos); Cq*}b4^;
} 9kX=99kf[
output.close(); =e!l=d|/
} )dIfr
catch(IOException e){e.printStackTrace ();} g?[&0r1
catch(Exception e){e.printStackTrace ();} Ph+X{|
} z(` }:t
bA<AG*
\aVY>1`
//读取保存的下载信息（文件指针位置） z'oiyXEE3
private void read_nPos() ){
{ W\qLZuQ
try{ G]mWaA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >'}=.3\
int nCount = input.readInt(); ey\m)6A$
nStartPos = new long[nCount]; E R]sDV
nEndPos = new long[nCount]; BF@5&>E
for(int i=0;i<nStartPos.length;i++) {s8U7rmML
{ << ;HY}s
nStartPos = input.readLong(); 7{An@hNh
nEndPos = input.readLong(); LZc$:<J<6
} lTr*'fX
input.close(); a\{1UD
} PwB g
catch(IOException e){e.printStackTrace ();} %nmY:}um
catch(Exception e){e.printStackTrace ();} [l':G]
} M.)}e7
`/w\2n
*K,hrpYR
private void processErrorCode(int nErrorCode) $' (QTEM
{ ) Kc%8hBv
System.err.println("Error Code : " + nErrorCode); *m$PH"
} MZ5Y\-nq\
6 tc:A5mK
rXY;m-
//停止文件下载 R>d@tr
public void siteStop() .5Knbc
{ )XP#W|;
bStop = true; -.{oqs$
for(int i=0;i<nStartPos.length;i++) 4N~+G `
fileSplitterFetch.splitterStop(); ,'C30A*p
?jri!]ux#
JYwyR++uo
} Ts(t:^
} a(@p0YpKT
//负责部分文件的抓取 /Fe:h>6
**FileSplitterFetch.java WGh. ;-
*/ \T`["<
package NetFox; @8=vFP'
kG)2%
wqlcLIJPR
import java.io.*; /Fv/oY
import java.net.*; mG831v?
K DYYB6|
4l&"]9D
public class FileSplitterFetch extends Thread { EJZ@p7*Oj
)?w&oIj5
-B1YZ/.rz"
String sURL; //File URL 'aD6>8/Hj
long nStartPos; //File Snippet Start Position .Gizz</P~
long nEndPos; //File Snippet End Position PSTu/^
int nThreadID; //Thread's ID Ag0]U
boolean bDownOver = false; //Downing is over r^$\t0h(U8
boolean bStop = false; //Stop identical 3{<R5wUo"
FileAccessI fileAccessI = null; //File Access interface b'velj3A
ajn-KG!A
fO].e"}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cYGRy,'gH
{ HWqLcQ d:P
this.sURL = sURL; rdO@X9z
this.nStartPos = nStart; 8q?;2w\l
this.nEndPos = nEnd; l8z%\p5cR
nThreadID = id; <rNtY,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fr+@HUOxsl
} _u>t3RUA
cV-i*L4X
OI+E (nA
public void run() ~}BJ0P(VMc
{ U,e'ZRU6
while(nStartPos < nEndPos && !bStop) (nLKQV 1
{ M[~Jaxw%
1h2H1gy5I3
TfJL+a0
try{ sf`PV}a1
URL url = new URL(sURL); TMK'(6dH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yI8 SQ$w0y
httpConnection.setRequestProperty("User-Agent","NetFox"); =f>HiF
String sProperty = "bytes="+nStartPos+"-"; B={/nC}G~
httpConnection.setRequestProperty("RANGE",sProperty); kl" ]Nw'C
Utility.log(sProperty); -Q#o)o
HOfF"QAR$
qNpu}\L
InputStream input = httpConnection.getInputStream(); N[pZIH5ho=
//logResponseHead(httpConnection); 5.wiTy
lr WLN
e#.\^
byte[] b = new byte[1024]; E#8_hT]5
int nRead; sxo;/~.p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u+i(";\
{ lX"bN=E?!
nStartPos += fileAccessI.write(b,0,nRead); sTkIR5Z
//if(nThreadID == 1) < kz[:n:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jo)6 %w]
} i3\~Qj;1
H)E^!eo
t:>x\V2m
Utility.log("Thread " + nThreadID + " is over!"); y_*n9 )Ct
bDownOver = true; 8W;2oQN7
//nPos = fileAccessI.write (b,0,nRead); Zd[OWF
} nTs/Q V
catch(Exception e){e.printStackTrace ();} :j@8L.<U
} ~b Rd)1
} &UL_bG}
GB>aT-G7q
7:TO\0]2n
//打印回应的头信息 9x?B5Ap[
public void logResponseHead(HttpURLConnection con) }p=g*Zo*C;
{ MAnp{
for(int i=1;;i++) X8b|]Nr
{ [SkKz>rC
String header=con.getHeaderFieldKey(i); qgx?"$ Z
if(header!=null) :6Pnie
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %hc'dZ
Utility.log(header+" : "+con.getHeaderField(header)); 1* ^'\W.
else 0z7L+2#b^
break; `B:"6nW6
} /Wu|)tx
} U'y,YtF@
:I \9YzSs@
@DuK#W"E u
public void splitterStop() ^O)ve^P
{ JB^Q\;$
bStop = true; $w)~xE5;
} ;#&fgj
1{Jb"
F~6#LT
} ^ S
X\\7$
b:kXNDc
/* ]GX \|1L
**FileAccess.java ZB[k{Y
*//文件访问(定位，写) W8]V
package NetFox; PK4`5uT
import java.io.*; 'eyJS`
?gSSli[
v$Uhm</|19
public class FileAccessI implements Serializable{ X3wX`V}
9JnY$e<&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =X-Tcj?3g
RandomAccessFile oSavedFile; ,a0pAj
long nPos; ;Lo&}U3F,!
HI`q1m.
3~Qd)j"<
public FileAccessI() throws IOException f<<rTE6
{ gsPl _
this("",0); UXH"si:
} !VP %v&jKm
!tXZ%BP.u
/(?@mnq_
public FileAccessI(String sName,long nPos) throws IOException uP@\#/4u
{ 2r&R"B1`(
oSavedFile = new RandomAccessFile(sName,"rw"); _w(ln9
this.nPos = nPos; (UYF%MA}"
oSavedFile.seek(nPos); 0 [8=c&F
} aDL*W@1S
*hdC?m._
R^n@.^8s
public synchronized int write(byte[] b,int nStart,int nLen) {v` 2sB
{ bk<FL6z z
int n = -1; >MG(qi
try{ 2(M6(xH>
oSavedFile.write(b,nStart,nLen); A}5fCx.{
n = nLen; 4woO;Gm
} l! v!hUb+
catch(IOException e) S~NM\[S
{ }]+xFj9[>
e.printStackTrace (); yGj.)$1},@
} ;o-yQmdh
W^\d^)
Pc_VY>Ty
return n; +fNvNbtA
} 'dJ/RJ~
G7@O`N8'
&:5\"b
} tX%`#hb?s
k?6z_vu
feX^~gM
/* j1-,Sqi
**SiteInfoBean.java r~7:daG*
*/ M4m$\~zf
package NetFox; zj|WZ=1*Wp
MYLsHIPC
Bs;|D
public class SiteInfoBean { 'ZP)cI:+X
lfN~A"X
JC#>Td
private String sSiteURL; //Site's URL atF?OP|{,w
private String sFilePath; //Saved File's Path v~|?3/{Q
private String sFileName; //Saved File's Name XYEv&-M`?w
private int nSplitter; //Count of Splited Downloading File 9z>z3,ftN
EME.h&A\G`
Uf\nFB? ^
public SiteInfoBean() v2+!1r7@
{//nSplitter的缺省值为5 ^tH#YlV4>9
//default value of nSplitter is 5 Te,$M3|
this("","","",5); XORk!m|
} sOU_j:A80;
"v-(g9(
Vz=auM1xZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3oy~=
{ FFKGd/:!
sSiteURL= sURL; \ I`p|&vG
sFilePath = sPath; 1|r,dE2k9
sFileName = sName; sTRJ:fR
this.nSplitter = nSpiltter; O) atNE
O,@~L$a:YZ
I=DxRgt
} 7q=G&e7
@A<PkpNL
?sz)J3
public String getSSiteURL() dt}_D={Be
{ Zw1U@5}A
return sSiteURL; ^P'{U26
} WjSc/3Qy
"Z=5gj
Dnf*7)X
public void setSSiteURL(String value) LOy0hN-$b
{ = u[#2!
sSiteURL = value; hr05L<?H
} *f%>YxF
Q]/Uq~m C
cD|Htt"
public String getSFilePath() M<PIeKIEB
{ "KX=ow#z|
return sFilePath; <^?1uzxH8A
} @=jWHS
cTTW06^
3*UR3!Z9 *
public void setSFilePath(String value) LUX*P7*B
{ D]G)j
sFilePath = value; ao_4mSB
} u+H; @
:#k &\f-Y
bg,9@ }"F
public String getSFileName() ?S$i?\Qh
{ ^O(=Vry
return sFileName; w;UqEC V
} 5irwz4.4
SP*fv`
~S,p?I
public void setSFileName(String value) 2%RNq<{Z_
{ Q\ /uKQ
sFileName = value; 7>XDNI
} RlT3Iz;
b45|vX+j
,)PiP/3B
public int getNSplitter() WrPUd{QM
{ WQyLf;!Lz
return nSplitter; zDhB{3-Q1{
} <fCKUc
eW5SFY.
Q+4tIrd+
public void setNSplitter(int nCount) h$eEn l}
{ d8-A*W[
nSplitter = nCount; FR2= las"z
} \^I>Q_LU
} akw,P$i
}Sy=My89r
n -(
/* su*Pk|6%
**Utility.java ~{sG| ;/!*
*/ !EUan
package NetFox; sf&]u;^DY
V%$/#sza
-*5Rnx|Y{
public class Utility { .920{G?l5
bR@p<;G|
=X.LA%Sf=u
public Utility() Z{&cuo.@<]
{ T~QJO0
X7k.zlH7T
@(r/dZc
} N?Lb
>pUtwIP
//线程睡眠 =UyLk-P w
public static void sleep(int nSecond) bfo["
{ PkI:*\R
try{ Q.K,%(^;a
Thread.sleep(nSecond); cGjPxG;
} sQkhwMg
catch(Exception e) lg^Z*&(
{ 5\z`-)
e.printStackTrace (); SdD6 ~LS
} #%DE;
} -Uml_/rd_
*}P~P$q%
//日志 m*JaXa
public static void log(String sMsg) g+z1
{ eM8}X[
System.err.println(sMsg); <)1qt 9
} F$)[kP,wtO
82l~G;.n3
&jmRA';sK
public static void log(int sMsg) K6R.@BMN
{ TYW&!sm
System.err.println(sMsg); p,#o<W
} ob8qe,_'
} J{Q|mD=
~@}Bi@*
eio4k-
/* B {>7-0
**TestMethod.java ZHa"isl$e
*/ <Y}R#o1Z
package NetFox; E>K!Vrh-L
V:joFRH9
{;2PL^i
public class TestMethod { 3W N@J6?
hIT+gnhh
>7 ="8
public TestMethod() i{`:(F5*
{ ///xx/weblogic60b2_win.exe v/_
try{ 0)gdB'9V_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uA<n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RCpR3iC2
SiteFileFetch fileFetch = new SiteFileFetch(bean); vX.VfY
fileFetch.start(); %KLpig
} 2WdyxjQ
catch(Exception e){e.printStackTrace ();} 7<*yS310
:=Nz}mUV
,y#Kv|R
} o2F)%TDY
K|epPGRr
|!4K!_y
public static void main(String[] args) A*\.NTM
{ g%=z_
new TestMethod(); DW[N|-L
} #"G]ke1l$
} lgk.CC
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