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)); aV%rq9Tp
} *LQY6=H
for(int i=0;i<nEndPos.length-1;i++) L6}x3
{ [5d][1=
nEndPos = nStartPos[i+1]; w)>z3Lm
} ?)<XuMh
nEndPos[nEndPos.length-1] = nFileLength; xb_:9
} 31\^9w__8
} gMMd=
@+vTGjHA
VNot4 62L
//启动子线程 1:Gd{z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5"]2@@b4
for(int i=0;i<nStartPos.length;i++) +>%+r
{ L#N.pd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0cU^ue%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _NW OSt
nStartPos,nEndPos,i); cCCplL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (:muxby%
fileSplitterFetch.start(); HcUz2Rm5XP
} K1WoIv<Ym
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K:Go%3~,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *F&&rsb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +Y[+2=lO
nEndPos = " + nFileLength); ?pY!sG
// fileSplitterFetch[nPos.length-1].start(); ==r|]~x
NX",e=
VO6y9X"
//等待子线程结束 /pN2Jst
//int count = 0; Wm&f+{LO+K
//是否结束while循环 +# >%bq x
boolean breakWhile = false; P!ICno6[e
. +?lID
;MI<J>s
while(!bStop) PTZ1oD
{ X'4 Yofs
write_nPos(); ]V("^.~$+C
Utility.sleep(500); ;a)\5Uy
breakWhile = true; @zq{#7%z
F}[;ytmUS
0)44*T
for(int i=0;i<nStartPos.length;i++) K)@Buu&,p
{ tAi9mm;k
if(!fileSplitterFetch.bDownOver) X*q C:]e
{ B+sqEj-
breakWhile = false; <}1%">RA
break; dG$0d_Pq
} .NC}TFN|
} %lmRe(M
if(breakWhile) WcG&W>
break; Zi)8KO[/0
8PS:yBkA|
O+J;Hp;\_
//count++; ![tI(TPq
//if(count>4) v[ '5X
// siteStop(); c[7qnSH
} dVfDS-v!
g_X7@Dt
h)`vc#"65k
System.err.println("文件下载结束！"); `:4cb$
} #^V"=RbD
catch(Exception e){e.printStackTrace ();} }(''|z#UE
} yBiwYk6
Nf'9]I
Q1[s{,
//获得文件长度 (Mh\!rMg
public long getFileSize() [40 YoVlfM
{ &3J#"9_S
int nFileLength = -1; {r8CzJ'f
try{ ]f~YeOB@
URL url = new URL(siteInfoBean.getSSiteURL()); k 'b|#c9c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :i$Z
httpConnection.setRequestProperty("User-Agent","NetFox"); Fgk/Ph3r
C%>7mz-v5
M(jH"u&f
int responseCode=httpConnection.getResponseCode(); 4UkLvL1x
if(responseCode>=400) VA.1JBQ
{ }6N|+z.cU
processErrorCode(responseCode); L]}|{<3\
return -2; //-2 represent access is error G9q0E|
} ?J?!%Mw
K gX)fj
e8.bH#
String sHeader; [_-K
MzG.Qh'z
@=c='V]
for(int i=1;;i++) Nb1lawC
{ 7d5x4^EYE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -y(V-
//Utility.log(in.readLine()); B=Os?'2[
sHeader=httpConnection.getHeaderFieldKey(i); u{,^#I}
if(sHeader!=null) 0%/(p?]M
{ 0iHI"9z
if(sHeader.equals("Content-Length")) 5ntP{p%>
{ ja2]VbB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dr o42#$Mo
break; opC11c/
} A9gl|II
} iz(+(M
else '3VrHL@@g
break; 9Ba<'wk/>"
} !%@{S8IP.v
} (" %yV_R
catch(IOException e){e.printStackTrace ();} ~/%){t/uLY
catch(Exception e){e.printStackTrace ();} mUbaR
jp]JFh;3
WXL.D_=+
Utility.log(nFileLength); |T%/d#b~
|&Q=9H*e
0l6%[U?o
return nFileLength; ]Y?$[+Y
} aRmS{X3
V2.K*CpZ7
#p>PNW-
//保存下载信息（文件指针位置） 4E)[<%
private void write_nPos() $;1~JOZh
{ 9[*kpMC
try{ y=Hl~ev`9
output = new DataOutputStream(new FileOutputStream(tmpFile)); ($TxVFNT
output.writeInt(nStartPos.length); z6qC6Ck|
for(int i=0;i<nStartPos.length;i++) 2H#vA
{ /MC\!,K
// output.writeLong(nPos); tWFJx}H
output.writeLong(fileSplitterFetch.nStartPos); 4o8!p\a
output.writeLong(fileSplitterFetch.nEndPos); 8] *{i
} ? 6l::M
output.close(); k*Kq:$9"
} ajAEGD2Zq
catch(IOException e){e.printStackTrace ();} 2~)]E#9
catch(Exception e){e.printStackTrace ();} ))N^)HR
} THJ+OnP
_xUXt)k
^9nM)[/C?
//读取保存的下载信息（文件指针位置） 2,\uY}4
private void read_nPos() }!LYV
{ P,wJ@8lv
try{ 0)NHjKP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fomkwN
int nCount = input.readInt(); v\c3=DbO
nStartPos = new long[nCount]; :FSkXe2yy0
nEndPos = new long[nCount]; `dK\VK^
for(int i=0;i<nStartPos.length;i++) '9)@U+yfQ
{ WA/\x
nStartPos = input.readLong(); BhjXNf9[
nEndPos = input.readLong(); `6A"eDa
} ]Vsze4>Z[
input.close(); c2nZd.SD|
} zSO[f
catch(IOException e){e.printStackTrace ();} ZS-9|EA<
catch(Exception e){e.printStackTrace ();} QEPmuG
} C*9m `xh
3,?y !
saV`-#
private void processErrorCode(int nErrorCode) Tla*V#:Ve
{ vBp5&*
System.err.println("Error Code : " + nErrorCode); ?>_.~b~
} 580t@?
k[p
F-Ea85/K@4
//停止文件下载 ;H^!yj5H
public void siteStop() 4Zq5
{ Xw%z#6l
bStop = true; -<sXvn
for(int i=0;i<nStartPos.length;i++) + |,CIl+
fileSplitterFetch.splitterStop(); ,y.0Cb0
JnZxP> 2B
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} dw-r}Qioe
} <3qbgn>}b
//负责部分文件的抓取 ^\!p;R
**FileSplitterFetch.java e:l 6;
*/ (_T&2%
package NetFox; u-Vnmig9
r?Vob}'Pt]
s|%</fMt9
import java.io.*; SnqLF /d
import java.net.*; Cur)|
6$f,DU
qr@,92_
public class FileSplitterFetch extends Thread { Czp:y8YX-
Q3DxjD
8+gn Wy
String sURL; //File URL r,}Zc W+
long nStartPos; //File Snippet Start Position 4q[r KNl
long nEndPos; //File Snippet End Position 'Zzm'pC
int nThreadID; //Thread's ID 1/n3qJyx2}
boolean bDownOver = false; //Downing is over |'.SOm9)*
boolean bStop = false; //Stop identical )_jO8)jB
FileAccessI fileAccessI = null; //File Access interface !CWqI)=
=Yfs=+O
v=4TU\b%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }S&{ &gh
{ )fa
this.sURL = sURL; Ort\J~O
this.nStartPos = nStart; ZG>OT@ GA
this.nEndPos = nEnd; >3bpa<M_
nThreadID = id; A!J5Wz>Q5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YJ9_cA'A
} 5E@V@kw
qg O)@B+
Z-Uq89[HZ
public void run() GgtL./m
{ ':,LZ A8A
while(nStartPos < nEndPos && !bStop) @l?%]%v|
{ J+zqu
iqU}t2vFrj
k\lj<v<vD
try{ \!PC:+uJ
URL url = new URL(sURL); wqyAEVea'8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E'ZWSpP
httpConnection.setRequestProperty("User-Agent","NetFox"); ~ce.&C7cR
String sProperty = "bytes="+nStartPos+"-"; p|((r?{
httpConnection.setRequestProperty("RANGE",sProperty); LOA 90.D
Utility.log(sProperty); gO5;hd[l
?YS`?Rr
J kA~Ol
InputStream input = httpConnection.getInputStream(); 3EFk] X
//logResponseHead(httpConnection); (3-G<E
'G^=>=w|Nv
"7l}X{b
byte[] b = new byte[1024]; \yxr@z1_b
int nRead; E,rPM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )#Id2b~
{ UJZa1p@L
nStartPos += fileAccessI.write(b,0,nRead); h{m]n!
//if(nThreadID == 1) pM=vW{"I/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2::T,Z
} f`cz@
gR6:J
AT%0i
Utility.log("Thread " + nThreadID + " is over!"); Nwc(<
bDownOver = true; ]}B&-Yp
//nPos = fileAccessI.write (b,0,nRead); D(&OyZ~Q+
} j)uIe)wZw
catch(Exception e){e.printStackTrace ();} l}wBthwCc
} e7;]+pN]J
} sJD"u4#y
}'{(rU
|QY+vO7fxj
//打印回应的头信息 &M2x`
public void logResponseHead(HttpURLConnection con) /i"EVN`t
{ sq^,l6es>
for(int i=1;;i++) A@#dv2JzP
{ 0'~?u'
String header=con.getHeaderFieldKey(i); M$GD8|*e
if(header!=null) Dn@ n:m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VcP#/&B|
Utility.log(header+" : "+con.getHeaderField(header)); U` U/|@6
else QZ`<+"a0
break; N@VD-}E
} 5 9X|l&/
} 52~k:"c
jPd<h{js
pQ>V]M
public void splitterStop() m/ukH{H1%
{ c{<3\
bStop = true; |joGrWv4
} r[lHYO
GwvxX&P
J h"]iN
} iN><m|
#K[ @$BY:
qq/Cn4fN8
/* 1Tl("XV3
**FileAccess.java 8]c`n!u=`
*//文件访问(定位，写) !6KEW,
package NetFox; }[Y):Yy
import java.io.*; X4TUi8ht!]
2O
GZ e )QH
public class FileAccessI implements Serializable{ ?=vwr,ir
KIS.4nt#d"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]uZH 0
RandomAccessFile oSavedFile; u-W=~EO5#
long nPos; zb4g\H 0
eyM3W}[S$/
&>/nYvuq-
public FileAccessI() throws IOException 3S9~rLrn?
{ T;%SB&
this("",0); ygPZkvZ
} fG{oi(T
07#!b~N
Hy6Np62
public FileAccessI(String sName,long nPos) throws IOException ,|H!b%ZW
{ ~% c->\Q
oSavedFile = new RandomAccessFile(sName,"rw"); 9+/|sU\.%
this.nPos = nPos; 1@ina`!1O
oSavedFile.seek(nPos); ^J G}|v3$
} ks;%f34
w"e2}iE7
+!<`$+W
public synchronized int write(byte[] b,int nStart,int nLen) W)_B(;$]
{ k9,"`dk@
int n = -1; Y}6)jzBV
try{ UvI!e4_
oSavedFile.write(b,nStart,nLen); aZ^lI 6@+4
n = nLen; ^>"?!lv
} :b=0_<G
catch(IOException e) bcZonS
{ IIPf5 Z}A
e.printStackTrace (); pxF!<nN1,
} -K!-a'J
,i|f8pZ
e,BJD>N ?
return n; G pd:k
} ;CW$/^QNr5
)Ga6O2:
|j+~Td3})&
} ieI-_]|[
H~@h #6
YszhoHYh
/* :Ls36E8f=
**SiteInfoBean.java EAfSbK3z
*/ u|ZO"t
package NetFox; 3LmHH =
oMPQkj;
Px8E~X<@
public class SiteInfoBean { \5Jv;gc\\
p.HA`R>
`#ztp)&
private String sSiteURL; //Site's URL ~IXfID!8
private String sFilePath; //Saved File's Path jt3SA [cy
private String sFileName; //Saved File's Name (nzt}i0
private int nSplitter; //Count of Splited Downloading File V6k9L*VP
`et<Z
*v9G#[gG
public SiteInfoBean() [>0r'-kI
{//nSplitter的缺省值为5 +M*a.ra0OF
//default value of nSplitter is 5 HL?pnT09
this("","","",5); YV msWuF
} vEsSqzc
2R!W5gs1<
}FXRp=s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3XRG"
{ D6t]E)FH
sSiteURL= sURL; U`Zn*O~/
sFilePath = sPath; q~3&f
sFileName = sName; lySaJd
this.nSplitter = nSpiltter; NSq"\A\
-AE/,@\P
G!\xc
} S%oGBY*Z
v<wT`hiKW
R32d(2%5K
public String getSSiteURL() z-DpLV
{ &u8c!;y$b
return sSiteURL; "DpQnhvbB
} JF gN
ry0 =N^
2}b bdXx
public void setSSiteURL(String value) v4$,Vt:7
{ ?KN_J
sSiteURL = value; 3(%,2
} #!/Nmd=Nj
b~gF,^w
LPO" K"'w
public String getSFilePath() S\A[Z&k0
{ hd~rC*I
return sFilePath; 5IK@<#wE
} 2. _cEY34
9m6j?CFG}
@-}]~|<
public void setSFilePath(String value) brWt
{ Ei-OuDM;)
sFilePath = value; (XJQ$n
} u W T[6R
.Dm{mV@*T
H~Cfni;
public String getSFileName() ^=G+]$8
{ 9x!y.gx
return sFileName; _SqrQ
} vknFtpx
BE~[%6T7
`vw.~OBl
public void setSFileName(String value) ;[9Is\
{ M6iKl
sFileName = value; bG)MG0<TT
} "+&<Qd2
;^]A@WN6_
j`B{w
public int getNSplitter() v%5(-
{ (#]KjpIK
return nSplitter; @{uc
} #EUgb7
{9 O`/|
+bW|Q>u
public void setNSplitter(int nCount) $P3nP=mf
{ ^q\zC%.
nSplitter = nCount; LS'=>s"
} 0 ,-b %X
} '9@R=#nd
"[yiNJ"kt
vuBA&j0C
/* *\", qMp
**Utility.java #cS,5(BM
*/ @XC97kGWp
package NetFox; |T*qAJ8c
R:N-y."La.
+ctv]'P_
public class Utility { K5&C}Ey1
LnS>3$t*
U.OX*-Cd
public Utility() +`-a*U94
{ /MH@>C _
Z"X*FzFo
8 -A7
} AW5g (
JxJntsn
//线程睡眠 +_P 2S
public static void sleep(int nSecond) :g#it@
{ Z;D3lbqE
try{ S8m&Rj3O&
Thread.sleep(nSecond); "~C#DZwt{
} D5u"4\g<&
catch(Exception e) #Ca's'j&f
{ Q%Q?q)x
e.printStackTrace (); &Q>'U6"%
} nD\os[ 3
} T0%TeFY
J|S^K kC
//日志 mcr#Ze
public static void log(String sMsg) "%*lE0Tx
{ (y*X8
System.err.println(sMsg); !#1A7[WN
} X388Gs;e
twmJ
mX@*2I
public static void log(int sMsg) y51D-vj
{ E^a`IA
System.err.println(sMsg); IQe[ CcM
} QYXx7h r=$
} 'hw@l>1\9
5l0rw)
`e>F<{ M6@
/* @n*D>g
**TestMethod.java k=2l9C3Z
*/ Cf[F`pFM
package NetFox; jDXGm[U
cE5Zxcn
?^ezEpW
public class TestMethod { `sy &dyM
3,I >.3
!r obau7
public TestMethod() /(ju
{ ///xx/weblogic60b2_win.exe +WN>9V0H
try{ Pl&`&N;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oV>AFs6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gj8[*3d
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8:?Q(M7
fileFetch.start(); I7z/GA\x
} :*:fun
catch(Exception e){e.printStackTrace ();} kah3Uhr~
jI`To%^Y
Kx185Q'W
} 0nq}SH
p6Dv;@)Yn
wx%nTf/Oa
public static void main(String[] args) ^@lg5d3F
{ f\_!N "HW
new TestMethod(); [j]J_S9jJ
} ec4%Wk2
} ]!G>8Rc
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