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)); !uhh_3RH
} &izk$~
for(int i=0;i<nEndPos.length-1;i++) p9eTrFDy?
{ nu6v@<<F>
nEndPos = nStartPos[i+1]; [-1Yyy1}
} ]F4|@+\9
nEndPos[nEndPos.length-1] = nFileLength; Jg@eGs\*
} ORt)sn&~d
} U-#vssJhk
8CRwHDB
FZfhiIf
//启动子线程 -9(nsaV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `12Y2W 9
for(int i=0;i<nStartPos.length;i++) D`PA@t
{ K# h7{RE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RYM[{]4b5F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /[|A(,N}{
nStartPos,nEndPos,i); ?aU-Y_pMe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E>kgEfzxP
fileSplitterFetch.start(); 2~@Cj@P]
} df9$k0Fx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xUIH,Fp-9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $3(E0\#O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $lF\FC
nEndPos = " + nFileLength); /+f3jy:d
// fileSplitterFetch[nPos.length-1].start(); .;37 e
jk5C2dy
\5F {MBx !
//等待子线程结束 U.J/ "}5`T
//int count = 0; ,sn 9&E
//是否结束while循环 ZV`o:Gd
boolean breakWhile = false; I_na^sh*
q`@8
%&iWc_"
while(!bStop) 0V'XE1h
{ !3Q^oR
write_nPos(); 5I0j>{U&
Utility.sleep(500); 3NrWt2?
breakWhile = true; i",oPz7
(Uk\O`)m
Uy$?B"Z
for(int i=0;i<nStartPos.length;i++) 8LlWXeD9
{ um$L;-2:
if(!fileSplitterFetch.bDownOver) Xl/2-'4
{ _8OSDW*D5t
breakWhile = false; trL8oZ6
break; Pol c.
} k;vhQ=
} @BqSu|'Du,
if(breakWhile) A@n//AZM
break; n<MreKixE
:SVWi}:Co1
sT>l ?L
//count++; %>,Kd6bdg
//if(count>4) Ai5D[ykX
// siteStop(); k E-+#p
} RGLi#:0_.x
,kE"M1W
TuzH'F
System.err.println("文件下载结束！"); ;V4f6[<]'z
} ]ru UX
catch(Exception e){e.printStackTrace ();} *vu
} 2$?j'i!
Ve4@^Jy;
\yY2 mr
//获得文件长度 O+o_{t\R
public long getFileSize() ~Q5 i0s%
{ \>
int nFileLength = -1; /@]@Tz@'
try{ P6;Cohfh
URL url = new URL(siteInfoBean.getSSiteURL()); 1lf]}V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {_]<mwd
httpConnection.setRequestProperty("User-Agent","NetFox"); Y!AQ7F
Yx<wYzD
.0]Odf:@
int responseCode=httpConnection.getResponseCode(); 1)ZdkTF@H
if(responseCode>=400) r<-@.$lf
{ :tBZu%N/N
processErrorCode(responseCode); d]Mjr2h
return -2; //-2 represent access is error F6-U{+KU$!
} Nrk/_0^
Eb9{
K?acRi
String sHeader; S$ 91L
Z;J{&OJ3qM
S$i3/t
for(int i=1;;i++) ,98`tB0
{ x-@6U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZVz`-hB
//Utility.log(in.readLine()); f}+8m .g2
sHeader=httpConnection.getHeaderFieldKey(i); ~bLhI
if(sHeader!=null) `r.
{ `rI[
if(sHeader.equals("Content-Length")) XnV$}T:?X
{ 3ypf_]<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); firiYL"=44
break; VseeU;q
} s@5r}6?M
} IP l]$j>N
else u YJL^I8M'
break; [7gwJiK
} !7aJfs2
} Bhw|!Y&%
catch(IOException e){e.printStackTrace ();} '@eH)wh@m)
catch(Exception e){e.printStackTrace ();} Y(P<9m:
T'e p&tNY
C\; $RH
Utility.log(nFileLength); ?\![W5uuXG
GYNLyd)
&Ch~$Wb^
return nFileLength; c9R|0Yn^J
} o|7 h
#"aL M6Cfs
LkIbvJCV
//保存下载信息（文件指针位置） [5QbE$
private void write_nPos() -O?&+xIK&
{ J1{ucFa
try{ >X-*Hu'U#
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,{u'7p
output.writeInt(nStartPos.length); '.d]n(/lZd
for(int i=0;i<nStartPos.length;i++) %&b70]S(
{ QLe<).S1B2
// output.writeLong(nPos); 7NDjXcuq
output.writeLong(fileSplitterFetch.nStartPos); 8S7 YVsDz"
output.writeLong(fileSplitterFetch.nEndPos); ouR(l;
} gPg2Ve0Qy
output.close(); hDHIi\%
} #dxS QmG
catch(IOException e){e.printStackTrace ();} P0XVR_TJf
catch(Exception e){e.printStackTrace ();} b#E!wMClS
} +K03yphZr
!0 -[}vvU
'7TT4~F
//读取保存的下载信息（文件指针位置） 9!|+GIjn
private void read_nPos() c9)5G+
{ lM-*{<B
try{ )m[dfeqd +
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "=\@ a=
int nCount = input.readInt(); .>{I S4
nStartPos = new long[nCount]; D!CuE7}
nEndPos = new long[nCount]; 1rQKHC:|
for(int i=0;i<nStartPos.length;i++) S K7b]J>
{ 'or8CGr^p
nStartPos = input.readLong(); !`EhVV8u-_
nEndPos = input.readLong(); C#4/~+
} caC(KK#<
input.close(); DX%D8atrr
} SHT^Etri
catch(IOException e){e.printStackTrace ();} <P4*7:jX
catch(Exception e){e.printStackTrace ();} f!aE/e\
} LX_{39?<{
;(,1pi7|
ZP^7`q)6
private void processErrorCode(int nErrorCode) I`8jJpGA
{ <{UjO
System.err.println("Error Code : " + nErrorCode); `Aa*}1
} zaoC
Wx-vWWx*Q
eGh7,wngH
//停止文件下载 -C<Ni
public void siteStop() bem-T`>'
{ 7JHS8C<]
bStop = true; Kk_h&by?
for(int i=0;i<nStartPos.length;i++) ('VHL!
fileSplitterFetch.splitterStop(); ' 5%`[&
A/#Xr
sCE2 F_xjL
} -!b@\=
} @CU~3Md*
//负责部分文件的抓取 y:3d`E4Xw
**FileSplitterFetch.java %:WM]dc
*/ '4}c1F1T_
package NetFox; <UMT:`h1MZ
Yab=p 9V;;
~ GW8|tw
import java.io.*; "~HV!(dRMC
import java.net.*; -L%2*`-L$
j1{\nP/
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public class FileSplitterFetch extends Thread { ]h6mJ{k
T11;LSD
K0Zq)<
String sURL; //File URL X ?lF,p
long nStartPos; //File Snippet Start Position |ZnRr
long nEndPos; //File Snippet End Position |U4t 8
int nThreadID; //Thread's ID Lc:DJA
boolean bDownOver = false; //Downing is over oK3aW6
boolean bStop = false; //Stop identical 78i"3Tm)w
FileAccessI fileAccessI = null; //File Access interface R1=ir# U|D
mv+K!T6
f8'$Mn,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O#5ll2?
{ , JUP
this.sURL = sURL; 1KtPq,
this.nStartPos = nStart; (ATCP#lF
this.nEndPos = nEnd; 8K/o/
nThreadID = id; mC}!;`$8p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >7^+ag~&
} "Nn+Zw43
)QvuoaJQ
+$x;FT&
public void run() w>W`8P_b@
{ f YuM`O
while(nStartPos < nEndPos && !bStop) ^sjL@.'m$N
{ L!]~J?)
sUP!'Av
@~l?hf
try{ >.-$?2
URL url = new URL(sURL); X;?Z_3I:5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *(4TasQu
httpConnection.setRequestProperty("User-Agent","NetFox"); Y/1,%8n
String sProperty = "bytes="+nStartPos+"-"; o-D,K dY
httpConnection.setRequestProperty("RANGE",sProperty); A|esVUo<3^
Utility.log(sProperty); 9IRvbE~2
_\tGmME37
#1C~i}J1
InputStream input = httpConnection.getInputStream(); 9C{\=?e;
//logResponseHead(httpConnection); n*oa J<o%
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<XHS@|
byte[] b = new byte[1024]; ]U,K]y[Bj
int nRead; U|%y`PZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h1 D#,
{ (BA2
nStartPos += fileAccessI.write(b,0,nRead); 426)H_wx
//if(nThreadID == 1) iC{~~W6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z{w{bf1&A
} "k${5wk#Fl
yeCR{{B/'
<9s=K\-
Utility.log("Thread " + nThreadID + " is over!"); f2#9E+IQ
bDownOver = true; cc%O35o
//nPos = fileAccessI.write (b,0,nRead); ($oO, c'z
} 4P>tGO&*x
catch(Exception e){e.printStackTrace ();} 4#qjRmt
} $pT%7jV}
} <}E^r_NvD
Bn"r;pqWiT
[wM<J$=2
//打印回应的头信息 m7XJe[O
public void logResponseHead(HttpURLConnection con) Qjj:r~l
{ Qn7l-:`?
for(int i=1;;i++) |m%M$^sZ}
{ &E{5k{Y
String header=con.getHeaderFieldKey(i); 6rnehv!p
if(header!=null) y%H;o?<WX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PSdH9ea
Utility.log(header+" : "+con.getHeaderField(header)); r]{fjw(~
else p.2>-L
break; :`Kr|3bQ
} @HfWAFT
} RT45@
{tE/Jv $
%(-YOTDr
public void splitterStop() -%=StWdb
{ i;0`d0^
bStop = true; ,<lxq<1I
} OU(z};Is6Z
?CS jn
?;,Al`/^
} '^l/e: (H3
]kmOX
gkpNT)
/* bH41#B
**FileAccess.java oPNYCE
*//文件访问(定位，写) y0qE::/H$
package NetFox; vtFA#})~
import java.io.*; oT5xe[{yj
K.2M=Q
g[;iVX^1&
public class FileAccessI implements Serializable{ f*~ 4Kv
%uGA+ \b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @"s\eL,r
RandomAccessFile oSavedFile; 5Ag>,>kJ6
long nPos; Uc0AsUu}?
Q:~w;I
@2_s;!K
public FileAccessI() throws IOException +k"dN^K]D
{ Et'C4od s
this("",0); wN)R !6
} kXC.rgal
bE>3D#V<
ABV\:u
public FileAccessI(String sName,long nPos) throws IOException ^+[o+
{ 2vnzB8"k
oSavedFile = new RandomAccessFile(sName,"rw"); FGx_qBG4|
this.nPos = nPos; 4Uf+t?U9
oSavedFile.seek(nPos); e#^|NQ<'A
} Z"?AaD[
fC3IxlG
s/[i>`g/9
public synchronized int write(byte[] b,int nStart,int nLen) ud:?~?j&w
{ U30)r+&
int n = -1; ^TWN_(-@
try{ ~rCnST
oSavedFile.write(b,nStart,nLen); n@L!{zY
n = nLen; l7{hq}@;cC
} 8"LaP3U
catch(IOException e) )O- x1U
{ %FFw!eVi
e.printStackTrace (); FA^x|C=$
} ~+7yi4(i
-e(2?Xq9
/&j4IlT
return n; Xs?7Whc6
} zFi+6I$
TiBE9
;oFaDTX]
} X}zKV
<(p1 j0_Q
l*Y~h3
/* 0HD1Ob^@
**SiteInfoBean.java 5,AQ~_,'\
*/ ,f?#i%EF&
package NetFox; 6 qKIz{;
UuT[UB=x5
)N=b<%WD
public class SiteInfoBean { /1li^</|p`
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=cC]8Pz?
private String sSiteURL; //Site's URL cn\& ;55v
private String sFilePath; //Saved File's Path f!$J_dz
private String sFileName; //Saved File's Name >qF KXzI
private int nSplitter; //Count of Splited Downloading File sf*SxdoZU
[!R%yD;
wCt+{Y3T
public SiteInfoBean() 4\OELU
{//nSplitter的缺省值为5 Ok`U*j
//default value of nSplitter is 5 )vU{JY;
this("","","",5); Ic=V:
} H+5]3>O-$
^LU[{HZV
k13/yiv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +~fu-%,k
{ M.8!BB7\8e
sSiteURL= sURL; w|nVK9.
sFilePath = sPath; EhFhL4Xdn
sFileName = sName; l.)N
this.nSplitter = nSpiltter; Ba+OoS
BWPYHWW}E
NUnP'X=J,
} a+~o: 5
ABHZ)OM
Lv^j l
public String getSSiteURL() x b0+4w|
{ }\0"gM
return sSiteURL; b/K&8C,c
} ai`:HhE
=!CuCV7$1O
yX~[yH+Pn
public void setSSiteURL(String value) m~U{ V9;*
{ F>b6fUtR
sSiteURL = value; Uqpvj90sw
} 0&nF Vsz
654%X(:q
R$@.{d&:w
public String getSFilePath() |Gf{}
{ {f&ga
return sFilePath; _uu:)%
} wwAT@=X*}
iE Oyc59
B7PmG f)b
public void setSFilePath(String value) .-|O"H$
{ 7}x-({bqy
sFilePath = value; )ED[cYGx
} PjP%,-@1
=0)^![y]v
xqtjtH9X
public String getSFileName() XGoy#h
{ "/'=gE
return sFileName; L,D>E
} /r%+hS
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PW`Tuj
public void setSFileName(String value) jFXU xf
{ Na6z,TW
sFileName = value; CbHNb~
} <M7*N.
j%}Jl
xKr,XZu
public int getNSplitter() `SwnKg
{ 0&\Aw'21
return nSplitter; heKI<[8l
} 2$o[
0/ Ht;(
'oHR4O*
public void setNSplitter(int nCount) _Nn!SE
{ ,![=_d
nSplitter = nCount; mCGcM^21-x
} fEjW7 c
} LNZ#%R~r
V3oAZ34)
1 ~7_!
/* C#~MR+;
**Utility.java oSl>%}
*/ ZYsFd_
package NetFox; EDo@J2A
@(cS8%wK
xB(:d'1|
public class Utility { x]ti3?w
6b/b}vl
':V_V. :
public Utility() S>,I&`yi
{ Flxo%g};
QC4T=E]`j
i-?zwVmn
} @;6}xO2
y2R=%EFh6
//线程睡眠 re!8nuBsA
public static void sleep(int nSecond) ]CZLaID~
{ vVYduvw
try{ V8yX7yx
Thread.sleep(nSecond); FZnHG;af
} ^JtHTLHL=
catch(Exception e) Y*k<NeDyn
{ lAk1ncx
e.printStackTrace (); i'wF>EBz
} V@S/!h+
} !7)ID7d
#'x?)AS
//日志 WQpJd7
public static void log(String sMsg) :6?&FzD`
{ 3-bcY4
System.err.println(sMsg); W6O.E
} ikhX5 &e
ku;nVV
2NknC>9(\
public static void log(int sMsg) @'*#]YU8
{ CLfb`rF
System.err.println(sMsg); !)3s <{k#
} cf'}*$[S
} -mJ&N
?0mJBA
0lCd,a2:
/* RuNH (>Eb
**TestMethod.java p^rX.?X
*/ ~5uNw*H
package NetFox; 6wB>-/'Y
0NtsFPO
]&U|d
public class TestMethod { Noxz kpMF
&t/<yq}{
9yo[T(8
public TestMethod() %"Q!5qH&
{ ///xx/weblogic60b2_win.exe iwJ-<v_:h
try{ eH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T(UYlLe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wmE,k1G
SiteFileFetch fileFetch = new SiteFileFetch(bean); R0mT/h2
fileFetch.start(); &H1D!N
} '1'1T5x~
catch(Exception e){e.printStackTrace ();} 9!HMQ
.eNwC.8i
s66XdM
} ~cBc&u:"
Z034wn\N
]8>UII,US
public static void main(String[] args) 'uACoME@
{ hav?mnVJ
new TestMethod(); N#['fg'
} ~_db<!a
} P .4b+9Tx
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