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)); QZ51}i
} qy|si4IU8,
for(int i=0;i<nEndPos.length-1;i++) VjVL/SO/
{ %7bZnK`C
nEndPos = nStartPos[i+1]; LK[%}2me
} X>y6-%@
nEndPos[nEndPos.length-1] = nFileLength; b}#ay2AR
} u0& dDZ
} oVSq#I4
;iEFG^'tG
KUqD<Jj?
//启动子线程 HNtl>H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?rn#S8nNx<
for(int i=0;i<nStartPos.length;i++) *b0f)y3RV
{ P*;zDQy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xz, sL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +b]+5!
nStartPos,nEndPos,i); <+c6CM$#}V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7&z`N^dz{
fileSplitterFetch.start(); "ewB4F[
} q9&d24|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^g56:j~?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =-qv[;%&6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #I.Wmfz
nEndPos = " + nFileLength); n7S~nk
// fileSplitterFetch[nPos.length-1].start(); Eo }mSd
xc+h Fx
F$Q@UVA
//等待子线程结束 *Q8d&$ ^
//int count = 0; &ii3Vlyzg
//是否结束while循环 )cy_d!
boolean breakWhile = false; -]h3s >t
Ag`:!*
sy|{}NkA!
while(!bStop) A[6$'IJ
{ 3%W R
write_nPos(); _ADK8a6%)
Utility.sleep(500); :A{ US9D
breakWhile = true; {s=$.Kg
8HyK;+ZkVd
ei8OLcw:x
for(int i=0;i<nStartPos.length;i++) 85fBKpEe
{ wb }W;C@
if(!fileSplitterFetch.bDownOver) x-_!I>l&
{ kOGpe'bV
breakWhile = false; _YH)E^If
break; P:")Qb2
} sc! e$@U
} v*nX
if(breakWhile) E30VKh |
break; J8"Cw<=O
g[P8
J8x>vC
//count++; &r;4$7
//if(count>4) Pxj?W'|
// siteStop(); VlVd"jW
} ? 1g<] ?
R9->.eE
j/R
System.err.println("文件下载结束！"); .TURS
} ;TK:D=p4
catch(Exception e){e.printStackTrace ();} av1*i3
} {qm(Z+wcmb
b7/1]
Y24:D7Q
//获得文件长度 >4.{|0%ut
public long getFileSize() j!;?=s
{ G!54 e
int nFileLength = -1; PT|W{RlNl
try{ $zTjh~ 9
URL url = new URL(siteInfoBean.getSSiteURL()); dOFxzk,g&R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H5Rn.n(|
httpConnection.setRequestProperty("User-Agent","NetFox"); i>S /W!F
C`D5``4
uE>2*u\
int responseCode=httpConnection.getResponseCode(); xOjCF&W
if(responseCode>=400) =J,aBp
{ Ywf.,V
processErrorCode(responseCode); |/g\N,]
return -2; //-2 represent access is error Zjt3U;Y
} DiAPs_@
7:1c5F~M
EY(@R2~#J
String sHeader; 9z,?DBMvc
<dzE5]%\
C,w$)x5kls
for(int i=1;;i++) ztG_::QtG]
{ DB yRP-TH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +>oVc\$
//Utility.log(in.readLine()); aT#R#7<Eg
sHeader=httpConnection.getHeaderFieldKey(i); 'Z-jj2t}
if(sHeader!=null) G1Cn[F;e
{ }0T1* .Cz
if(sHeader.equals("Content-Length")) i+&*W{Re
{ "6n~,$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pb.-Z@
break; A8OV3h6]
} S*:b\{[f>
} ;""V s6
else v"L<{HN
break; 2Ni$ (`"
} _tN"<9v.
} :JSOj@s
catch(IOException e){e.printStackTrace ();} m5sgcxt/
catch(Exception e){e.printStackTrace ();} +GWeu0b(~
z@cL<.0CE
&gkloP@
Utility.log(nFileLength); pd,5.d
kzGD*
RaAi9b[/S
return nFileLength; C}+w<
} 5>7ECe*
(?&X<=|"
jGEUl=W
//保存下载信息（文件指针位置） )5Kzq6.
private void write_nPos() JPgV7+{b[
{ '1=t{Rw
try{ MZE8Cvq0
output = new DataOutputStream(new FileOutputStream(tmpFile)); X#(?V[F]
output.writeInt(nStartPos.length); x<"e} Oo
for(int i=0;i<nStartPos.length;i++) ]]+wDhxH
{ :a3Pnq$]E
// output.writeLong(nPos); 5A/G?
output.writeLong(fileSplitterFetch.nStartPos); 8|?$KLz?F>
output.writeLong(fileSplitterFetch.nEndPos); y1/$dn
} :h N*
output.close(); APuG8 <R,
} :M1S*"&:
catch(IOException e){e.printStackTrace ();} G6Z2[Ej1
catch(Exception e){e.printStackTrace ();} 4_`+&
} \no[>L]
'rU [V+
y-{^L`%Mk
//读取保存的下载信息（文件指针位置） ]E88zWDY`
private void read_nPos() ooByGQ90V:
{ )=;0
try{ on+ c*#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <r,l
int nCount = input.readInt(); 4W~pAruwr
nStartPos = new long[nCount]; 9rtcI[&?0
nEndPos = new long[nCount]; Uw5z]Jck
for(int i=0;i<nStartPos.length;i++) &?/h#oF@\
{ #Z}\;a{vZ
nStartPos = input.readLong(); d$kGYMT"
nEndPos = input.readLong(); s*:J=+D]G
} VLN=9
input.close(); :sFP{rFx~
} 7Rk eV
catch(IOException e){e.printStackTrace ();} |~W!Y\l-
catch(Exception e){e.printStackTrace ();} YrjF1hJ
} -d6|D?}S
mKPyM<Q
L\5j"] }`
private void processErrorCode(int nErrorCode) Ezm ~SY
{ .ev'd&l.
System.err.println("Error Code : " + nErrorCode); B+wSLi(
} Io{)@H"f
s<xD$K~rM
Wj/.rG&tE
//停止文件下载 $k V^[
public void siteStop() KDuM;
{ ykxjT@[
bStop = true; ]0zXpMNI
for(int i=0;i<nStartPos.length;i++) ?z171X0
fileSplitterFetch.splitterStop(); k(><kuJ`3
U"A]b(54
'AE)&56
} %:N6#;l M
} ITRv^IlF
//负责部分文件的抓取 iQZgs@
**FileSplitterFetch.java m]+g[L?-
*/ Xp{+){Iu
package NetFox; ,Zb]3
0ho+Y@8
+%=Ao6/#
import java.io.*; "CB*
import java.net.*; @/ wJW``;
T c4N\Cy
+y>D3I
public class FileSplitterFetch extends Thread { eRD?O
Z+=WgEu1
wZ,9~P7
String sURL; //File URL ^vLHs=<
long nStartPos; //File Snippet Start Position q[nX<tO
long nEndPos; //File Snippet End Position .KGW#Qk8
int nThreadID; //Thread's ID _0 USe
boolean bDownOver = false; //Downing is over (01M0b#
boolean bStop = false; //Stop identical ~C{d2i
FileAccessI fileAccessI = null; //File Access interface bPAp0}{Fu
:O{`!&[>L
*{P"u(K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -wy$ ?Ha
{ k+{-iPm{
this.sURL = sURL; >o>r@;
this.nStartPos = nStart; 4WG~7eIgy
this.nEndPos = nEnd; gdRwh
nThreadID = id; ^TJn&k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YW}q@AY7
} KRf$VbuL
t]#y}V
x^qmYX$'1b
public void run() ><viJ$i
{ WQ<J<$$uu
while(nStartPos < nEndPos && !bStop) { ,/mQ3
{ 3 ~0Z.!O
iJk`{P_
z[B*sbS
try{ QDRSQ[\
URL url = new URL(sURL); PCH&eTKN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RRqHo~*0
httpConnection.setRequestProperty("User-Agent","NetFox"); )dbi
String sProperty = "bytes="+nStartPos+"-"; L@2T
httpConnection.setRequestProperty("RANGE",sProperty); }a,j1r_Hl&
Utility.log(sProperty); 5*xk8*
FylL7n
mEmznA
InputStream input = httpConnection.getInputStream(); #Sr_PEo _
//logResponseHead(httpConnection); E'?yI'~=
TggM/@k
IExo#\0'6
byte[] b = new byte[1024]; SEq_37
int nRead; -~~"}u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -tAdA2?G
{ 2i;G3"\
nStartPos += fileAccessI.write(b,0,nRead); |G~LJsXW!v
//if(nThreadID == 1) 7c1xB.g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4P(Y34j
} fHCLsI
5e~\o}]
#:_qo
Utility.log("Thread " + nThreadID + " is over!"); UM(tM9
bDownOver = true; r j#K5/df
//nPos = fileAccessI.write (b,0,nRead); vcy}ZqWBO
} NDEltG(
catch(Exception e){e.printStackTrace ();} .$y}}/{j?[
} ]y>)es1
} -Mx"ox
!Low%rP
r5h}o)J
//打印回应的头信息 Sg(fZ' -
public void logResponseHead(HttpURLConnection con) ~^cx a%
{ , \|S BS
for(int i=1;;i++) s]Nh9h
{ oA%8k51>~K
String header=con.getHeaderFieldKey(i); CvKXVhf0$J
if(header!=null) BoE;,s>]NW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9E4H`[EQ
Utility.log(header+" : "+con.getHeaderField(header)); `=g9Rg/<
else wN\%b}pp
break; o@mZ6!ax3
} K9B_o,
} ?2zVWZ
l5F>v!NA
D]S@U>]M!
public void splitterStop() _]a8lr+_-
{ ;,![Lar5L
bStop = true; T&c0j(
} @.;] $N&J
#;sUAR?]
(lq7 ct
} fCdd,,,}
Kq e,p{=
r!N)pt<g
/* &^3KF0\Q
**FileAccess.java o^hI\9
*//文件访问(定位，写) REUWK#>
package NetFox; wYQTG*&h
import java.io.*; mr dG-t(k
y! he<4
_-eF &D
public class FileAccessI implements Serializable{ SIv8EMGo
"jqC3$DKI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^-?5=\`5
RandomAccessFile oSavedFile; S=H<5*]g
long nPos; ++n"` ]o,
6nqG;z-IXJ
2\h}6DGx2
public FileAccessI() throws IOException .VG$`g"
{ V#["Z}
this("",0); \]ouQR.t@\
} X]ow5{e
Dnn$-W|NC
gKy@$at&
public FileAccessI(String sName,long nPos) throws IOException VU3xP2c:
{ l!CWE
oSavedFile = new RandomAccessFile(sName,"rw"); px;5X4U
this.nPos = nPos; i1k(3:ay<
oSavedFile.seek(nPos); yQ5&S]Xk$$
} c`}-i6
ivg:`$a[
?tS=rqc8oW
public synchronized int write(byte[] b,int nStart,int nLen) NBHS
{ $Y.Z>I;
int n = -1; 7OY<*ny
try{ iU3)4(R
oSavedFile.write(b,nStart,nLen); T&Z%=L_Q
n = nLen; ,RIGV[u
} Q;{[U!\:
catch(IOException e) gZ%wmY
{ ,_;+H*H>"
e.printStackTrace (); l^aG"")TH.
} RzCC>-
qOy3D~
vFz%#zk>
return n; V\Oe]w
} ^%l~|w
0!X;C!v;
H%N!;Jz=
} par|j]
gI8r SmH
&Fo)ea
/* PhBdm'
**SiteInfoBean.java }%(e`[?1
*/ 7L~LpB
package NetFox; E +\?|q !T
> w:+nG/r
fDyFkhc
public class SiteInfoBean { &2IrST{d:V
/N6sH!w
1,@-y#V_
private String sSiteURL; //Site's URL @8WG
private String sFilePath; //Saved File's Path i(DoAfYf/q
private String sFileName; //Saved File's Name <cu? g
private int nSplitter; //Count of Splited Downloading File Q79& Q04XN
\Y.&G,?
%qA@)u53
public SiteInfoBean() C"l_78
{//nSplitter的缺省值为5 "q@OMf
//default value of nSplitter is 5 lrSdFJ%
this("","","",5); {TT@Mkz_QC
} !u~h.DrvZ
p;Ezmz
v~^c-]4I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?^]29p_
{ YT!QY@qw
sSiteURL= sURL; SN2X{Q|*
sFilePath = sPath; S~jl%]
sFileName = sName; mD}&X7
this.nSplitter = nSpiltter; iC-WQkQY
N<c98
E~oQ%X~
} #N%ATV
]D|sQPi]F
JqWMO!1
public String getSSiteURL() 0v6(A4Y
{ !wH7;tU
return sSiteURL; @k+Z?Hp
} 4T#B7wVoM
g-^Cf
3&Dln
public void setSSiteURL(String value) (I3:u-A
{ V9xZH5T8^
sSiteURL = value; *o]Q<S>lH
} _nw=^zS
{SH+lX0]{
ZUGuV@&-T
public String getSFilePath() _Eq*
{ =hE5 ?}EP+
return sFilePath; (ov=D7>t0
} }'HJVB_
:%GxU;<E{
oXw}K((|
public void setSFilePath(String value) d"zbY\`
{ uv*OiB"
sFilePath = value; "0Xa?z8"
} Bi?.w5
cU}j Whu
l!Q |]-.@
public String getSFileName() [s?H3yQ.
{ A#9@OWV5f
return sFileName; cJ9:XWW
} l:NEK`>i
(WT0j
J/(3: a>
public void setSFileName(String value) ".+wz1
{ Id8^6FLw
sFileName = value; $Yfm>4
} EoLF7j<W
lhZWL}l
1B~H*=t4h
public int getNSplitter() [ bv>(a_,
{ oQJK}9QR
return nSplitter; 9vc3&r
} arf`%9M
{E!"^^0`
1M&n=s _
public void setNSplitter(int nCount) 12)~PIaF
{ ju8mO&
nSplitter = nCount; =x "N0p
} w-Zb($_
} #5HJW[9
?8wFT!J
z,XM|-"#<K
/* 1G/bqIMg63
**Utility.java Ve>*KHDSt
*/ S3nA}1R
package NetFox; F?2(U\k#
vPuPSE%M
xM85^B'
public class Utility { k1y&'3%
/$zYSP)YT
b6!?K!imT
public Utility() <Q)6N!Tp^
{ (n7v $A
e"en ma\_
-05zcIVo
} GRz`fO
`T $lTP
//线程睡眠 qe!`LeT#
public static void sleep(int nSecond) HKO00p7
{ PQAN,d
try{ C`OdMM>D
Thread.sleep(nSecond); TL@_m^SM
} GIQ/gM?Pv
catch(Exception e) C/dqCUX:
{ KfJF9!U*?
e.printStackTrace (); mMO:m8W
} _QCspPT' c
} ,vP9oY[n
G`E%uyjG$j
//日志 *g&[?y`UC
public static void log(String sMsg) ?bbu^;2*f
{ ?b, eZ+t
System.err.println(sMsg); 6 )eO%M`
} &,Dh*)k
eG26m_S=
M`HXUA4
public static void log(int sMsg) J'tc5Ip!}V
{ 2vWJ|&|p
System.err.println(sMsg); >69xl^Gd
} R7cY$K{j
} 5o\yhYS:
ZQND^a:
En3Q%
/* 7dI+aJ
**TestMethod.java 0[}"b(O{
*/ Md'd=Y_0
package NetFox; 5T}$+R0&
!I5_ln
UzFd@W u#
public class TestMethod { AR'q2/cw
e#IED!U
esmQ\QQ^1
public TestMethod() 1g{`1[.QO
{ ///xx/weblogic60b2_win.exe 0rY<CV;fZ
try{ 9ZUG~d7_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{Hk27kt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uc~PKU?tO
SiteFileFetch fileFetch = new SiteFileFetch(bean); D8slSX`6j
fileFetch.start(); O-:#Q(H!
} yJ8WYQQMG
catch(Exception e){e.printStackTrace ();} nab:y(]$/
jy{T=Nb
x, a[ p\1
} 95^w" [}4Q
h";G vjy
("o<D{A
public static void main(String[] args) Y>Q9?>}Q
{ P"W$ZX
new TestMethod(); ;^xlDN
} ftF?T.dx
} OM{-^
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