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)); "[LSDE"(
} VC6S4FU4K
for(int i=0;i<nEndPos.length-1;i++) [Bz'c1
{ uPtHCP6
nEndPos = nStartPos[i+1]; sa71Vh{
} &2!F:L
nEndPos[nEndPos.length-1] = nFileLength; .7nr:P
} &$?i
} XU}sbbwu
]GS@ub
.2jG~_W[
//启动子线程 pSq3\#Twr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )n[ oP%
for(int i=0;i<nStartPos.length;i++) GAlAFsB
{ bh8IF,@a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 32flOi:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Odo"S;)
nStartPos,nEndPos,i); -;?5<>zZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w]{NaNIeq1
fileSplitterFetch.start(); B0:[3@P7
} gr/o!NC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bkn- OG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S>]Jc$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cXJtNW@
nEndPos = " + nFileLength); "DFj4XKXY9
// fileSplitterFetch[nPos.length-1].start(); &!3=eVg
3d{v5. C#X
Y.Er!(pz
//等待子线程结束 jnK8 [och
//int count = 0; kd9GHN;7
//是否结束while循环 !S/hH%C
boolean breakWhile = false; RPvOup
!@_( W
!8|]R
while(!bStop) up~l4]b+
{ vYD>m~Qc^
write_nPos(); {9<2{$Og
Utility.sleep(500); l.i"Z pik
breakWhile = true; )y7SkH|
pPm9v_G
#_+T@|r
for(int i=0;i<nStartPos.length;i++) sq_N!
{ eXaa'bTx
if(!fileSplitterFetch.bDownOver) 3mIX9&/
{ sg(L`P
breakWhile = false; H7e/6t<x
break; #zcp!WE.OI
} <%JRZYZ
} ]]s_ 8u3
if(breakWhile) sX3Vr&r
break; xw5E!]~D
F6T@YSP
bp6 La`+
//count++; $a6&OH/
//if(count>4) vpY|S2w)Bp
// siteStop(); *|x2"?d-F:
} -#b-@sD
-;z&">
Q^v8n1
System.err.println("文件下载结束！"); 7cn"@h rJ
} ;<#fZ0(l;
catch(Exception e){e.printStackTrace ();} hGH{Xp[mW
} <?P UF,
^yKP 99(
j=)%~@
//获得文件长度 PZ-|W
public long getFileSize() i4.s_@2Y
{ S\Qh#yFT
int nFileLength = -1; #](k,% 2
try{ 4];Qpln
URL url = new URL(siteInfoBean.getSSiteURL()); }[PbA4l.g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y9m'RFZr
httpConnection.setRequestProperty("User-Agent","NetFox"); {=7W;uL
HLAYmXX"w
V9"Kro
int responseCode=httpConnection.getResponseCode(); joifIp_
if(responseCode>=400) =MG
{ )\uy 0+b
processErrorCode(responseCode); 5cP]
return -2; //-2 represent access is error p;) ;Vm+8
} _f,q8ZkSr
>ofS'mp
:Qu!0tY
String sHeader; <W vuW6
MUNeGqv
{!B0&x
for(int i=1;;i++) TUZ-4{kV"
{ -(>x@];r0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ##,i<
//Utility.log(in.readLine()); 4aAr|!8|h!
sHeader=httpConnection.getHeaderFieldKey(i); 0i$jtCCL(
if(sHeader!=null) kT UQ8U
{ #JZf]rtp
if(sHeader.equals("Content-Length")) C^r3r6
{ +U^dllL7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ap\2={u^|
break; 2?ZHWS>U
} lw? f2_fi
} w"-bO ~5h
else /w!b2KwV
break; nP?(9;3*
} p7!q#o
} P-No;/!B#
catch(IOException e){e.printStackTrace ();} -z0,IYG }
catch(Exception e){e.printStackTrace ();} [j}%&$
~SZ0Yu:X
n<lU;
Utility.log(nFileLength); Q=gVxS
8ne'x!1 D
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return nFileLength; e\.|d<N?
} R]/F{Xs
^k^%w/fo
b_Ba0h=
//保存下载信息（文件指针位置） I]Wb\&$
private void write_nPos() )TyL3Z\>(
{ D2>EG~xWq
try{ %dL|i2+*8
output = new DataOutputStream(new FileOutputStream(tmpFile)); "=|yM~V
output.writeInt(nStartPos.length); Ff& VBm
for(int i=0;i<nStartPos.length;i++) LjXtOF
{ *kL1r w6
// output.writeLong(nPos); -.g5|B
output.writeLong(fileSplitterFetch.nStartPos); d2.eDEOsC
output.writeLong(fileSplitterFetch.nEndPos); f]5bAs
} ET_}x7
output.close(); >g93Bj*
} )J (ekfM
catch(IOException e){e.printStackTrace ();} >6ch[W5k@
catch(Exception e){e.printStackTrace ();} $F G4wA
} &.<{c `-
:!tQqy2
HK&F'\'}
//读取保存的下载信息（文件指针位置） =q[3/'2V$?
private void read_nPos() zK:/ 1
{ K N0S$nW+
try{ ;=)CjC8)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xvp{F9~qT
int nCount = input.readInt(); #JuO
nStartPos = new long[nCount]; 'L3 \I
nEndPos = new long[nCount]; ]pb;q(?^
for(int i=0;i<nStartPos.length;i++) [rPW@|^5
{ TmX~vZ
nStartPos = input.readLong(); ,[Cl'B
nEndPos = input.readLong(); o?p) V^7
} }tv-
input.close(); gMI%z2]'-
} B7}-g"p$/
catch(IOException e){e.printStackTrace ();} ,{8~TVO
catch(Exception e){e.printStackTrace ();} 9KXp0Q?-$
} w=#&(xm0
P$]Vb'Fz
g-}Vu1w0{6
private void processErrorCode(int nErrorCode) ,fET.s^|U
{ ,Z>RvLl
System.err.println("Error Code : " + nErrorCode); (eO0Ic[c
} A2rr>
j*QY_Ny*
J4lE7aFDA~
//停止文件下载 W11_MTIU
public void siteStop() *A,=Y/
{ [(btpWxb^
bStop = true; kmov(V
for(int i=0;i<nStartPos.length;i++) G0]q(.sOy
fileSplitterFetch.splitterStop(); 8% 1hfj
zG& N5t96X
KM0#M'dXy
} HNU[W8mg8
} c}v:X Slh7
//负责部分文件的抓取 hH[JY(V
**FileSplitterFetch.java LDPo}ogs
*/ Nob(bD5SpE
package NetFox; ?m?e2{]u,
_FdWV?
}clFaT>m?
import java.io.*; 8zVXQ!'
import java.net.*; &]vd7Q.t
u3k+Xg:
XkdNWR0
public class FileSplitterFetch extends Thread { T5-4Q
G|^gaj'9
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String sURL; //File URL 7ky(g'
long nStartPos; //File Snippet Start Position 2s6Vy
long nEndPos; //File Snippet End Position S~6<'N&[
int nThreadID; //Thread's ID HHEFX9u
boolean bDownOver = false; //Downing is over Iv/yIS
boolean bStop = false; //Stop identical `+zr PpX
FileAccessI fileAccessI = null; //File Access interface kN]#;R6
P'Y8 t
@KS:d\l}U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;WGY)=-gv
{ `RmB{qgB
this.sURL = sURL; l0Pg`wH,
this.nStartPos = nStart; u:,B"!
this.nEndPos = nEnd; 0|GxOzNd
nThreadID = id; :K8T\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,Y!T!o}1
} ~s5Sk#.z5
DK)qBxc8
%eT/:I
public void run() x!YfZ*
{ IRS^F;)
while(nStartPos < nEndPos && !bStop) 1km=9[;w'
{ #d|.BxH
d[$1:V
:'!?dszS
try{ `L;I/Hp
URL url = new URL(sURL); C)ChF`Ru':
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eq4<
httpConnection.setRequestProperty("User-Agent","NetFox"); t"BpaA^gO
String sProperty = "bytes="+nStartPos+"-"; 6Jj)[ R\5=
httpConnection.setRequestProperty("RANGE",sProperty); +ZZiZ&y
Utility.log(sProperty); 2G'G45Q
;G\rhk
BO[A1'>
InputStream input = httpConnection.getInputStream(); <XLATS8Y
//logResponseHead(httpConnection); GzR;`,_O/
3}T&|@*
F%Mlid;1
byte[] b = new byte[1024]; Bo~wD|E2
int nRead; RyM2CQg[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qK#* UR0%
{ hnY^Z_v!
nStartPos += fileAccessI.write(b,0,nRead); qBwqxxTc
//if(nThreadID == 1) YInW)My.h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `/|=eQ")o@
} XG^
S%T1na^x
rB7(&(n>^
Utility.log("Thread " + nThreadID + " is over!"); ipyO&v
bDownOver = true; mC93 &0
//nPos = fileAccessI.write (b,0,nRead); $jntT(V
} $qEJO=v
catch(Exception e){e.printStackTrace ();} zf S<X
} X:!%"K%}
} #/1Bam6
fcBSs\\C~
P]x@h
//打印回应的头信息 5_i&}c23Vn
public void logResponseHead(HttpURLConnection con) }Jtaq[y\r
{ ; 6zu!
for(int i=1;;i++) p1D-Q7F
{ $Z,+aLmb
String header=con.getHeaderFieldKey(i); vLC&C-f
if(header!=null) [+%*s3`c#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dGfWRqS]
Utility.log(header+" : "+con.getHeaderField(header)); Fb}9cpz{
else p75w^
break; t+#Ss v8
} @z,'IW74V
} 8<G@s`*
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:L?zk"0C
public void splitterStop() ^:q(ksssY
{ [Q*kom :
bStop = true; jBQQ?cA
} XR&*g1
nOB ]?{X
f9rToH
} 4EELaP|%
PNG'"7O
T]myhNk
/* W=b5{ 6
**FileAccess.java IW46-;l7
*//文件访问(定位，写) BkJcT
package NetFox; y^XwJX-f
import java.io.*; :[rx|9M6
+X&B'
l5MxJ>?4%B
public class FileAccessI implements Serializable{ q@\D5F% >
v3/cNd3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t (1z+
RandomAccessFile oSavedFile; "pH+YqJ$
long nPos; a2i
JrQN-e!
+j<Nu)0iY
public FileAccessI() throws IOException 0s8S`hCn>
{ <E^:{J95
this("",0); J3'"-,Hv
} Soa.thP
GM%|mFqeu
ucn aj|
public FileAccessI(String sName,long nPos) throws IOException _A,m@BCz
{ o0/03O
oSavedFile = new RandomAccessFile(sName,"rw"); 6>"0H/y,
this.nPos = nPos; "&r1&StO
oSavedFile.seek(nPos); OVd"'|&6_
} A6sBObw;
Wb|IWnH$
V`%m~#Me
public synchronized int write(byte[] b,int nStart,int nLen) ,4\vi|
{ [$./'-I]
int n = -1; DB*IVg
try{ p5bH-km6
oSavedFile.write(b,nStart,nLen); _ x7Vyy5
n = nLen; hVlL"w*1
} J0>Q+Y
catch(IOException e) mr/^lnO
{ `$i`i'S
e.printStackTrace (); A$oYw(m#
} ['c:n?
8@r+)2
mxWaXb
return n; jem$R/4"
} u54+oh|,M
B!Qdf8We
MTF:mLJ
} pa+y(!G
RuHJk\T+
X-ml0 =M[
/* !q/?t XM!
**SiteInfoBean.java YY.;J3C
*/ jeJGxfii
package NetFox; b'ew Od=
?d_Cy\G
];< [Cln%
public class SiteInfoBean { E]gKJVf9[
ypml22)kz
O|OPdD
private String sSiteURL; //Site's URL 8RocObY_W
private String sFilePath; //Saved File's Path 7{b|+0W
private String sFileName; //Saved File's Name *|4~ 0w
private int nSplitter; //Count of Splited Downloading File R{*p\;
ly{~X
5[@4($q8
public SiteInfoBean() mMa7Eyaf
{//nSplitter的缺省值为5 Mk^o*L{H
//default value of nSplitter is 5 'Oq}BVR&
this("","","",5); l,d8%\
} k1%Ek#5
bhg"<I
K&S~IFy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7#<|``]zNf
{ MLp5Y\8*
sSiteURL= sURL; |_ ;-~bmb
sFilePath = sPath; PPmZ[N9(;
sFileName = sName; $y`|zK|G-
this.nSplitter = nSpiltter; {UwJg
+]AE}UXZoh
V#Wd
} qg'm<[
:1AOund
>u6kT\|^C
public String getSSiteURL() cOS|B1xG
{ !IT']kA
return sSiteURL; D'</eJ
} )~WxNn3rx
]5} =r
8^HMK$
public void setSSiteURL(String value) @jjp\~
{ } #$Y^ +UN
sSiteURL = value; RJGf@am&
} 4}l,|7_&I
3J@#V '
:yw0-]/DD
public String getSFilePath() (?~F}u v
{ eyy&JjVs
return sFilePath; C YnBZ
} gBresHrlH
lZb1kq%9g
JSO>rpO
public void setSFilePath(String value) hNP|
{ RMsr7M4<91
sFilePath = value; koaH31Q
} ncu> @K$n
B<_T"n'#b
PN<Y&/fB
public String getSFileName() U4Qc$&j>
{ )LnHm
return sFileName; Dx iCq(;
} !dmI}<@&k
cITQ,ah
nfl6`)oW
public void setSFileName(String value) I_N"mnn@Nr
{ Px)VDs=k
sFileName = value; P3(u+UI3
} +dR$;!WB3
011 _(v
/&dC?bY
public int getNSplitter() a*=\-;HaZ
{ 3wa }p^
return nSplitter; zYF'XB]4
} 2D&tDX<
3\6jzD
5P+3D{
public void setNSplitter(int nCount) pH)V:BmJ
{ !*EHr09N7
nSplitter = nCount; 1G$kO90
} `N2zeFG
} <gJ|Wee
~"{Kjr#R
aS:17+!
/* ]vhh*
**Utility.java BxlpI[yWq
*/ b\H~Ot[i
package NetFox; o^_z+JFwb
#jK{)%}mA
BDc*N]m}B1
public class Utility { A*E$_N
f`H}Y!W(
O:#t> ;
public Utility() PK!=3fK4\F
{ /ijj;9EB
Nqewtn9n
hDzKB))<w
} Q!|. ,?V
=as]>?<
//线程睡眠 qDNqd
public static void sleep(int nSecond) ~ia#=|1}
{ W<v?D6dFq
try{ Up)b;wR
Thread.sleep(nSecond); WWHT;ST
} \MX>=
catch(Exception e) \S1WF?<,
{ Pgs4/
e.printStackTrace (); GS\-
} js'*:*7
} z`m-Ca>6
6e/2X<O
//日志 ;]+kC
public static void log(String sMsg) ;sCX_`t0E
{ + ECV|mkk
System.err.println(sMsg); N{ ;{<C9Z
} 3-~_F*%ST
-9vAY+s.
:n{rVn}G
public static void log(int sMsg) 5|wQeosXxI
{ enK4`+.7
System.err.println(sMsg); JKGUg3\~
} ,k+jx53XV
} &I<R|a
|&h!#Q{7l
c;BQ$je}
/* z35n3q
**TestMethod.java @N1ta-D#
*/ Su-LZ'C\
package NetFox; wW]|ElYR=
`p*7MZ9-
>0T0K`o
public class TestMethod { E&GUg/d
^ D?;K8a-l
;(TBg-LEK
public TestMethod() -GH#nF3G
{ ///xx/weblogic60b2_win.exe qm@c[b
try{ )u'oI_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nU||Jg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _QkU,[E
SiteFileFetch fileFetch = new SiteFileFetch(bean); x!]ZVl]
fileFetch.start(); pJK puoiX
} HOtays,#<}
catch(Exception e){e.printStackTrace ();} =DGaK0n
h:Npi `y
H /*^$>0Uo
} bXC;6xZV
]%"Z[R
([`-*Hy
public static void main(String[] args) C(7LwV
{ dD@T}^j *|
new TestMethod(); 80c\O-{
} / QSK$ZDC
} J:5%ff~r\
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