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)); +=v|kd
} A2 rRYzN;
for(int i=0;i<nEndPos.length-1;i++) v?J2cL
{ l!2.)F`x
nEndPos = nStartPos[i+1]; TDFv\y}yc
} 3/D fsv
nEndPos[nEndPos.length-1] = nFileLength; 7}MWmS^8j
} oUH\SW8?
} &x}JC/u]fd
E2l.
l1msXBC
//启动子线程 '=5N?)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~Km8-b(&
for(int i=0;i<nStartPos.length;i++) $vd._j&
{ a&JAF?k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [dUEe@P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JT<J[Qz5
nStartPos,nEndPos,i); :Li)]qN.I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]d0Dd")n
fileSplitterFetch.start(); N|; cG[W
} .,4&/cd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !&kOqc5:t<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >ObpOFb%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -Q/Dbz#-
nEndPos = " + nFileLength); ;1WclQ!(
// fileSplitterFetch[nPos.length-1].start(); UA^E^$f:
7G(X:!
+!rK4[W'
//等待子线程结束 b/)UN*~
//int count = 0; Pj$a$C`Z
//是否结束while循环 ^gy(~u
boolean breakWhile = false; 8EQ;+V
s<{c?4T
"D+QT+sD
while(!bStop) 5|Uub,
{ W cnYD)
write_nPos(); Wr;)3K
Utility.sleep(500); H]-nm+
breakWhile = true; Nt)9-\T
a2zo_h2R
%(i(ZW "
for(int i=0;i<nStartPos.length;i++) m@~HHwj
{ /*[a>B4-q
if(!fileSplitterFetch.bDownOver) CBc}N(9
{ 8w$cj'
breakWhile = false; z&eJ?wb
break; PO#FtG
} FU<rE&X2:
} ezL*YM8?@
if(breakWhile) 5<61NnZ
break; ]l4\/EW6
,YH.n>`s+
R!`#pklB
//count++; 9P]TIV.
//if(count>4) ls=<c<
// siteStop(); 1i{B47|
} &]5<^?3
Zhw _L
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System.err.println("文件下载结束！"); 7+0hIKrFC
} Z]aSo07
catch(Exception e){e.printStackTrace ();} YWTo]DJV
} sM4N`$Is23
8<P.>u
3B,nHU
//获得文件长度 L\"$R":3{d
public long getFileSize() Z|)~2[Roa
{ b{sFN!
int nFileLength = -1; q.*qZ\;K
try{ \]^|IViIQ
URL url = new URL(siteInfoBean.getSSiteURL()); ,y^By_1wS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]M_)f
httpConnection.setRequestProperty("User-Agent","NetFox"); Vi]D](^!
Q)v8hNyUmA
sQR;!-j
int responseCode=httpConnection.getResponseCode(); ]O 2_&cs
if(responseCode>=400) b{(:'.
{ Q.nEY6B_
processErrorCode(responseCode); CnO$xE|{
return -2; //-2 represent access is error xx%WIY:}
} r+>9O
S_^"$j
3p7*UVR"
String sHeader; thOCzGJ$
H`fkds
X,~8) W
for(int i=1;;i++) \4V'NTjB
{ GU!|J71z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aPWFb.JO4
//Utility.log(in.readLine()); [QeKT8
sHeader=httpConnection.getHeaderFieldKey(i); "5{\0CfS
if(sHeader!=null) }L@YLnc%
{ E_$ST3
if(sHeader.equals("Content-Length")) X!&=S!}
{ ;DGp7f#9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <F&S
break; p<Zf,F}
} rq$%
} $UKDXQF"
else e&E*$G@.7
break; qWo|LpxWt
} b\}`L"
} "|f;
catch(IOException e){e.printStackTrace ();} e7<~[>g)
catch(Exception e){e.printStackTrace ();} A=BpB}b
T%Z`:mf
~]N% {;F}
Utility.log(nFileLength); 2PRGwK/
ctj.rC)6n
Oyz=|[^,W
return nFileLength; dNIY`u
} MECR0S9
7 0KZXgBy_
m"u 9AOHk
//保存下载信息（文件指针位置） _w)0r}{
private void write_nPos() U;ev3
{ (RGl, x:
try{ lnTl"9F
output = new DataOutputStream(new FileOutputStream(tmpFile)); Yh"R#
output.writeInt(nStartPos.length); S7-?&[oeJ
for(int i=0;i<nStartPos.length;i++) s*rtm
{ Rb#?c+&#
// output.writeLong(nPos); 5FzG_ w
output.writeLong(fileSplitterFetch.nStartPos); 10*U2FY)]
output.writeLong(fileSplitterFetch.nEndPos); G$ipWi
} )5&Wt@7Kj`
output.close(); >4bOM@[]
} |`#[jHd
catch(IOException e){e.printStackTrace ();} yl|+D]
catch(Exception e){e.printStackTrace ();} =$fxK
} O>H4hp
K&Zdk (l)
mh|M O(
//读取保存的下载信息（文件指针位置） jt?R a1Z
private void read_nPos() z^~fVl
{ =n%?oLg^
try{ ^]OD+v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]kc]YO7i%R
int nCount = input.readInt(); P%.9g
nStartPos = new long[nCount]; V5R``Tp
nEndPos = new long[nCount]; \\)3:1X
for(int i=0;i<nStartPos.length;i++) 6VRVk7"
{ 2N`Vx3
nStartPos = input.readLong(); aNfgSo05@n
nEndPos = input.readLong(); (n#
} M1VRc[ RRo
input.close(); S tn[M|
} =T;%R^@
catch(IOException e){e.printStackTrace ();} )p(XY34]
catch(Exception e){e.printStackTrace ();} ))u$j4V
} /ZX8gR5x
{_PV~8u
VAV@Qn
private void processErrorCode(int nErrorCode) cND2(<jx:
{ Wu%;{y~#}
System.err.println("Error Code : " + nErrorCode); G| ^tqI
} }?"f#bI
yU&A[DZQ
90M:0SH
//停止文件下载 ]oZ$,2#;~
public void siteStop() h|_G2p^J+"
{ M`AbH19
bStop = true; 1 BVivEG
for(int i=0;i<nStartPos.length;i++) ;z!~-ByzL
fileSplitterFetch.splitterStop(); 2x'JR yef
.b5B7x}
d7P| x
} n8J';F =P
} o KX!{
//负责部分文件的抓取 t:$p8qR
**FileSplitterFetch.java t4h5R
*/ H<dm;cU
package NetFox; QZ%_hvY[%>
5h1FvJg
o{m$b2BW
import java.io.*; G`gYwgU;
import java.net.*; B +_D*a
u]CW5snz
SC"=M^E
public class FileSplitterFetch extends Thread { qDOx5.d
oQFpIX;\m
no^I![_M
String sURL; //File URL 9 bGN5.5
long nStartPos; //File Snippet Start Position Va?wG3w
long nEndPos; //File Snippet End Position RVX-3FvP
int nThreadID; //Thread's ID ;w[|IRa
boolean bDownOver = false; //Downing is over :@19,.L
boolean bStop = false; //Stop identical B3e{'14
FileAccessI fileAccessI = null; //File Access interface %q(n'^#Z.y
LR'F/.Dx
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /tx_I(6F?|
{ &&TQ0w&T
this.sURL = sURL; KYd2=P6
this.nStartPos = nStart; @I#@%"AW
this.nEndPos = nEnd; ppfBfMX
nThreadID = id; MX6;ww
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `fc2vaSH =
} O>)8< yi$
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*}A J7]
public void run() |_ E)2b:h
{ WZ;f3 "
while(nStartPos < nEndPos && !bStop) .u)Po;e`
{ pgfI1`h
Q_qc_IcM y
mp%i(Y"vp
try{ o1-Zh!*a*
URL url = new URL(sURL); 9Jaek_A`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X{<j%PdC
httpConnection.setRequestProperty("User-Agent","NetFox"); OV Iu&6#
String sProperty = "bytes="+nStartPos+"-"; a*KB'u6&
httpConnection.setRequestProperty("RANGE",sProperty); cPkN)+K
Utility.log(sProperty); dy#dug6j
Z#nj[r!l}
[uW{Ap~2
InputStream input = httpConnection.getInputStream(); Ga"$_DyM
//logResponseHead(httpConnection); '72ZLdi}-
mS0*%[S {
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byte[] b = new byte[1024]; ~g~z"!K
int nRead; VctAQ|h^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d*7 Tjs{\
{ C/tn0
nStartPos += fileAccessI.write(b,0,nRead); -D`*$rp,
//if(nThreadID == 1) TBvv(_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hA/K>Z
} sGc4^Z%l?
n\ZDI+X
0ppZ~}&
Utility.log("Thread " + nThreadID + " is over!"); #p6#,PZ
bDownOver = true; 5<Xq7|Jt
//nPos = fileAccessI.write (b,0,nRead); &iId<.SiJ
} Oy&Myjny<
catch(Exception e){e.printStackTrace ();} IH'DCY:
} >jq~5HN
} "#qyX[\
Ks{^R`Oau
M~zdcVTbH
//打印回应的头信息 Zii<jZ.)<
public void logResponseHead(HttpURLConnection con) P<km?\Xp(
{ -_4U+Cfmtl
for(int i=1;;i++) MX xRM~
{ xmT(yv,
String header=con.getHeaderFieldKey(i); Ud\Jc:DG
if(header!=null) Ti=~ycwi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \:'=ccf
Utility.log(header+" : "+con.getHeaderField(header)); AJI,>I,}}
else Wu,'S;>C
break; bH~ue5q
} qR--lvO
} 7fgA)dU:K
BOoLs(p
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public void splitterStop() BI3Q~ADV
{ MrXhVZ"d*
bStop = true; )?:V5UO\
} 7eqax33f
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|l 03,dOF
} W52AX.Nm
mh2t ' O
a.y_o50#T
/* S=n,unn#t
**FileAccess.java 3BDAvdJ4.
*//文件访问(定位，写) 4Sfv
package NetFox; e@Q<hb0<eU
import java.io.*; YrS%Yvhj0
0-oR { {
I;S[Ft8d
public class FileAccessI implements Serializable{ $RuJm\f
rLw,?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ont4-AP
RandomAccessFile oSavedFile; 9_n!.zA<
long nPos; i<YatW~Pu
|-bSoq7t
cP''
public FileAccessI() throws IOException L6fc_Mo.EE
{ b?hdWQSW7
this("",0); 7q<I7Wt
} QU2\gAM
Rf+ogLa=
%`t;5kmR
public FileAccessI(String sName,long nPos) throws IOException @V Bv}Jo
{ ]!E|5=q
oSavedFile = new RandomAccessFile(sName,"rw"); ^z-e"
this.nPos = nPos; hw:zak#j,
oSavedFile.seek(nPos); 559znM=
} -n?}L#4%8
hu%UEB
RXP0 4
public synchronized int write(byte[] b,int nStart,int nLen) (Eq0 |"cj
{ \Azl6`Em
int n = -1; x00"d$!
try{ AkrUb$ }
oSavedFile.write(b,nStart,nLen); yQ?N*'}$
n = nLen; <.s=)}'`P
} /%\E2+6
catch(IOException e) X3NHQMI
{ {w$1_GU
e.printStackTrace (); 7SE\(K=<%
} I83ZN]
#/Y t4n
AF g*
return n; qsk8#
} -9Wx;u4]o
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} (Hb i+IHV
8zS't2 u
X2hV)8Sk
/* x]&V7Y
**SiteInfoBean.java $`W.9
*/ U$@p"F@P
package NetFox; WHk/Rg%<
axW3#3#`
-yHVydu=
public class SiteInfoBean { RUC V!L
*lRP ZN
/Y_F"GQ
private String sSiteURL; //Site's URL L']EYK5
private String sFilePath; //Saved File's Path dPwe.:
private String sFileName; //Saved File's Name 3 [: x#r
private int nSplitter; //Count of Splited Downloading File $=uyZTYF)}
}A3(g$8KR
|FGt'
public SiteInfoBean() b&f;p}C24
{//nSplitter的缺省值为5 `d2}>
//default value of nSplitter is 5 )eop:!m
this("","","",5); }\k"azQ`
} -Qgu6Ty
]S<y,d-
O?/\hZ"&c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i% 19|an
{ NTS tk{s,
sSiteURL= sURL; +h_'hz&HlS
sFilePath = sPath; Me;@/;c(
sFileName = sName; tz\7,yGT
this.nSplitter = nSpiltter; s7e)Mt
{|= 8wB
Sh(
} ; >Tko<
gO_{(\w*
6"U&i9
public String getSSiteURL() [hSE^ m
{ Q]9H9?}N?
return sSiteURL; fz#e4+oH
} 5<\&7P3y
Y0fX\6=h
xZZW*d_b
public void setSSiteURL(String value) Is&z~Xy/
{ ]S4TX
sSiteURL = value; ~n9BN'@x
} L!s/0kBg
,R]hNjs-{
S G|``}OA
public String getSFilePath() Tu2BQ4\[
{ 2mN>7Tj:
return sFilePath; WW82=2rJ9
} 7t=e"|^
^Lr)STh
Y+75}]B
public void setSFilePath(String value) DP**pf%j
{ YzJ\< tkp
sFilePath = value; _Bm/v^(
} N+%E=D>
:=WiT_M
RO"c+|Py
public String getSFileName() E:/G!1
{ :bFCnV`Q
return sFileName; }UNRe]ft$
} roT$dL P)w
Fw? ;Y%
]4wyuP,up
public void setSFileName(String value) 5m{!Rrb
{ 8##-fv]
sFileName = value; I)Y ^_&=
} ,4wVQ(,?cd
CKwrE]h
&.D3f"
public int getNSplitter() MT9c:7}[&
{ Qfx(+=|
return nSplitter; Hf!o6 o
} Hv2t_QjKT
T^.;yU_B?
Lsa&A+fru
public void setNSplitter(int nCount) +InAK>NZ'
{ 7WK^eW"y8
nSplitter = nCount; T[*1*303
} Z ?`
} 9SF2
l]D?S]{a
Lh.?G#EM
/* ?;Dh^mc
**Utility.java Q`k=VSUk
*/ 17g\XC@ Cl
package NetFox; S^0Po%d
aC:Sy^Tf
`(s&H8x#
public class Utility { P @N7g`u3}
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epM;u
public Utility() ;BzbWvBo
{ oe,I vnt
N"Y)
zvv<w@rX
} jf25Ky~
]G.ttfC
//线程睡眠 :ad
public static void sleep(int nSecond) 1vKc>+9
{ (n:d {bKV
try{ _Kdqa%L !
Thread.sleep(nSecond); :L gFd
} 6d/;GyG
catch(Exception e) AuIb>@a
{ iIWz\FM
e.printStackTrace (); T(t@[U2^
} kSx^Uu*
} L1=+x^WQ
%xZYIYKf
//日志 w@w(AFV9/
public static void log(String sMsg) i}teY{pyc
{ s;V~dxAiv
System.err.println(sMsg); `kb]tf
} v5STe`
9}p>='
.?{rd3[ec
public static void log(int sMsg) xVk|6vA7
{ ^uB9EP*P
System.err.println(sMsg); ?m.WqNBH7
} S9/oBxGN
} 8xs}neDg*
cojtQD6
(T;4'c
/* ?/ xk
**TestMethod.java +>3XJlZV
*/ |iN!V3#S
package NetFox; hTgWqp
PwP;+R};|
Y_m/? [:
public class TestMethod { A&EVzmj-+X
Cm@e^l!
z}I=:
public TestMethod() $:IOoS|e
{ ///xx/weblogic60b2_win.exe ~ [L4,q
try{ l&3f<e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NIZN}DnP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h^_Sd"l3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~2 L{m[s|
fileFetch.start(); E"d\N-I
} _<tWy+.
catch(Exception e){e.printStackTrace ();} :|cC7,S
"|P8L| @*
irj{Or^k
} g/Q"%GN,
5(BB`)
_,*ld#'s
public static void main(String[] args) W/03L, 1
{ o,o,(sII
new TestMethod(); 9G njJ
} hP1}Do
} 1aEM&=h_W
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