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)); H!Od.$ZIX
} 8odVdivh
for(int i=0;i<nEndPos.length-1;i++) HhpP}9P;
{ @i`gR%
nEndPos = nStartPos[i+1]; w+MdQ@'5
} }`MO}Pz
nEndPos[nEndPos.length-1] = nFileLength; o?b%L
} ;T_9;RU<'b
} AH7k|6ku<*
fg1y@Dj/&
p/:5bvA
//启动子线程 S1+#qs{5a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .Gv~e!a8
for(int i=0;i<nStartPos.length;i++) 1z`,*eD7
{ }UO,R~q~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D~y]d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <N*>9S,}
nStartPos,nEndPos,i); asF-mf;D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <G&v
fileSplitterFetch.start(); _4W#6!
} srSTQ\l4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T9$U./69-L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kDz.{Ih
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UP`q6]P
nEndPos = " + nFileLength); $YC~02{
// fileSplitterFetch[nPos.length-1].start(); $e_ps~{7$
Wp]EaYt2D
g|zK%tR_P
//等待子线程结束 c[YjGx
//int count = 0; ,qfa,O
//是否结束while循环 o2|(0uN'
boolean breakWhile = false; dL\8^L
P$QjDu-
<-?B#
while(!bStop) aE%VH ;?
{ _qg6( X
write_nPos(); %b?Pasf.
Utility.sleep(500); &-*nr/xT
breakWhile = true; k|_2aQ02
"4`%NA
<oO,CXF
for(int i=0;i<nStartPos.length;i++) G<z)Ydh_
{ @Dy.HQ~
if(!fileSplitterFetch.bDownOver) O<3,n;56Z
{ wY95|QS
breakWhile = false; d"78:+
break; 47RYpd
} q>[% C5
} :9#`|#uh
if(breakWhile) Zb 2
break; J v#^GNm
Lm?*p>\Q
G4}q*&:k
//count++; wgyO%
//if(count>4) V4-=Ni]k
// siteStop(); ]R@G5d
} V!P3CNK
V9VP"kD
x.yL'J\)
System.err.println("文件下载结束！"); *p3P\ H^5
} SSXS
catch(Exception e){e.printStackTrace ();} d0B+syl&4l
} eTc`FXw`
v2{O67j} o
k~R[5W|'
//获得文件长度 [FL I+;gY
public long getFileSize() , .I^ekF
{ 2UF94
int nFileLength = -1; mc'p-orAf
try{ ~D5MAEazS
URL url = new URL(siteInfoBean.getSSiteURL()); ddP,_.0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `VsGa
httpConnection.setRequestProperty("User-Agent","NetFox"); RuZ;hnE&
DKl7|zG4
cnthtv+(~
int responseCode=httpConnection.getResponseCode(); 9ojhI=:
if(responseCode>=400) gcxk'd
{ dmz3O(]$
processErrorCode(responseCode); YZl%JX
return -2; //-2 represent access is error %?hLo8
} 6W=:`14
\2pFFVT
A232"p_
String sHeader; E5 oD|'=WA
jyhzLu
/ yi:Q0
for(int i=1;;i++) a1SOC=.M;
{ BUinzW z{a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mj=|oIMwT
//Utility.log(in.readLine()); <&:&qngg
sHeader=httpConnection.getHeaderFieldKey(i); pXv[]v
if(sHeader!=null) j\f$r,4
{ ap^=CEf
if(sHeader.equals("Content-Length")) ^gzNP#A<'o
{ fR4l4 GU?)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &|}IBu:T
break; J~3T8e#
} )V3(nZY
} 5iddB $
else r)(BT:2m
break; DA)v3Nd
} 6;frIl;
} `?^w
catch(IOException e){e.printStackTrace ();} ""3m!qn#
catch(Exception e){e.printStackTrace ();} %8CT -mQ
+esNwz_
6bKO;^0
Utility.log(nFileLength); n/oipiYx
*}ee"eHs
xeM':hD.o
return nFileLength; eD{ @0&
} 7. 9s.*
WG/J4H`Od
M |?p3%
//保存下载信息（文件指针位置） =+}}Sv2
private void write_nPos() %;(|KrUN
{ 8V|jL?a~
try{ 4Sstg57x~
output = new DataOutputStream(new FileOutputStream(tmpFile)); QeeC2
output.writeInt(nStartPos.length); %}MA5 t]o
for(int i=0;i<nStartPos.length;i++) K=Z]#bm
{ L\Fu']l
// output.writeLong(nPos); O%K?l}e
output.writeLong(fileSplitterFetch.nStartPos); _SIs19"lR
output.writeLong(fileSplitterFetch.nEndPos); +GYMJK`S+
} G:c8`*5Q
output.close(); 8#]7`o
} )xvx6?Ah|
catch(IOException e){e.printStackTrace ();} R^yZG{?t
catch(Exception e){e.printStackTrace ();} _d[2_b1
} LlA`QLe
rw8J:?0x
nN=:#4 >Y
//读取保存的下载信息（文件指针位置） pO/SV6N
private void read_nPos() vbA7I<;
{ A2|o=mOH
try{ ))IgB).3M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =F%wlzF:
int nCount = input.readInt(); kyxSIQ^
nStartPos = new long[nCount]; -[=AlqL
nEndPos = new long[nCount]; d@6:|auO
for(int i=0;i<nStartPos.length;i++) Dl zmAN
{ 1(?CNW[
nStartPos = input.readLong(); ! [|vx!p
nEndPos = input.readLong(); >2lAy:B5
} n4vXm
input.close(); loeLj4""
} n=G>y7b
catch(IOException e){e.printStackTrace ();} 53`9^|:
catch(Exception e){e.printStackTrace ();} JMirz~%ib
} 7"n)/;la
vfJ3idvo*w
r%y;8$/-
private void processErrorCode(int nErrorCode) E+m]aYu"
{ xxLgC;>[
System.err.println("Error Code : " + nErrorCode); J-, H6u
} hsHVX[<5`
+q #Xy0u
S2'`|uI
//停止文件下载 8K@"B
public void siteStop() {+C%D'
{ ;&+[W(7Sy
bStop = true; @ate49W
for(int i=0;i<nStartPos.length;i++) $Yx6#m}[M
fileSplitterFetch.splitterStop(); 1Lm].tq
VY+(,\)U
r/CEYEJ&X
} C.yY8?|
} di3 B=A>3
//负责部分文件的抓取 1u"R=D9p,=
**FileSplitterFetch.java -+3be(u
*/ (orrX Ez
package NetFox; %_B:EMPd
n_""M:XH
1DEO3p
import java.io.*; |8&-66pX
import java.net.*; IWjR0
@9OeC O
CrnB{Z4L
public class FileSplitterFetch extends Thread { 8- dRdQu]
Cz'xGW{
w1wXTt
String sURL; //File URL b@=zrhQ
long nStartPos; //File Snippet Start Position r?64!VS;
long nEndPos; //File Snippet End Position &mh Ln4^
int nThreadID; //Thread's ID _:wZmZU}
boolean bDownOver = false; //Downing is over Bz~ -2#l
boolean bStop = false; //Stop identical uz*d^gr}
FileAccessI fileAccessI = null; //File Access interface wXc,FD$
wn &$C0
yB-.sGu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wENzlXeOP
{ CdX`PQ
this.sURL = sURL; _FL<egK
this.nStartPos = nStart; LWD.
this.nEndPos = nEnd; C=>B_EO
nThreadID = id; E;9Z\?P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %)pP[[h
} fucUwf\_
@(Z( /P;:
{J{1`@
public void run() Xa4GqV9M/-
{ JYPxd~T/-
while(nStartPos < nEndPos && !bStop) {5SfE$r
{ .FuA;:@%\
,,S9$@R
S2ark,sp6
try{ DYX-5~;!
URL url = new URL(sURL); =KV@&Y^x4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0[.3Es:_
httpConnection.setRequestProperty("User-Agent","NetFox"); _HwpPRVP/
String sProperty = "bytes="+nStartPos+"-"; iu+3,]7Fm
httpConnection.setRequestProperty("RANGE",sProperty); KZ]r8
Utility.log(sProperty); FS8S68
5Yl6?
G=1m]>I8
InputStream input = httpConnection.getInputStream(); s,w YlVYf!
//logResponseHead(httpConnection); K${}r0
w}d}hI
`Z:3`7c
byte[] b = new byte[1024]; sv' Gt1&"Z
int nRead; KCD5*xH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P 4QkY#v
{ zHV|-R
nStartPos += fileAccessI.write(b,0,nRead); `0?^[;[u[
//if(nThreadID == 1) i-,'.w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HM):"
} x:qr\Rz
6%%PP8.F
[yC"el6PM
Utility.log("Thread " + nThreadID + " is over!"); Ae6("Oid
bDownOver = true; _-/x;C
//nPos = fileAccessI.write (b,0,nRead); W<Z$YWr
} 9 Va40X1
catch(Exception e){e.printStackTrace ();} !_dR'
} tn{8u7
} =5Wp&SM6
izf~w^/
JR)/c6j
//打印回应的头信息 ,%Z&*n
public void logResponseHead(HttpURLConnection con) xorTL8
{ gfm;xT/y
for(int i=1;;i++) q3)wr%!k5D
{ jN6b*-2
String header=con.getHeaderFieldKey(i); H} 6CKP}
if(header!=null) ]\BUoQ7I/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -;>#3O-
Utility.log(header+" : "+con.getHeaderField(header)); EE]=f=3
else \TUE<<?1s
break; 87<9V.s2
} 8R}K?+]
} YjLe(+WQ
z]$>+MH_
[4XC#OgA
public void splitterStop() 0[)VO[
{ x@m<Ym-
bStop = true; E:w:4[neh
} P"F{=\V1`<
Q]rqD83((
?'sXgo.}
} Yj|]Uff8O
/C$ xH@bb
HabzCH
/* 7Ms90oE/c
**FileAccess.java iCrxV{
*//文件访问(定位，写) sx5r(0Z
package NetFox; qVBL>9O*.
import java.io.*; n+;vjVS%
JMlV@t7y<
hD q2-X}
public class FileAccessI implements Serializable{ }1U*A#aN7K
}+0z,s~0.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @B`Md3$7
RandomAccessFile oSavedFile; os$nL'sq
long nPos; ^u)rB<#BR
xU}M;4kH~
f^9&WT
public FileAccessI() throws IOException *eUc.MX6x
{ |nY~ZVTt/
this("",0); hNbIpi=
} V=}1[^
eko]H!Ov(
)acV-+{
public FileAccessI(String sName,long nPos) throws IOException ?`AGF%zp
{ 6GINmkA
oSavedFile = new RandomAccessFile(sName,"rw"); <>=mCZ2
this.nPos = nPos; 4D"4zp7
oSavedFile.seek(nPos); (oaYF+T
} aB"xqh)a}T
'jvpNn
8S U%
public synchronized int write(byte[] b,int nStart,int nLen) c Zvf"cIs
{ 2z\;Q8g){r
int n = -1; $}tjS3klr
try{ "C74
oSavedFile.write(b,nStart,nLen); s@!$='|
n = nLen; R1%y]]*-P
} `ZGcgO<c\
catch(IOException e) 'fY9a(Xt.
{ 9%!dNnUk
e.printStackTrace (); vV^dm)?
} ]b}B2F'n
}htPTOy5
R^8{bP
return n; $j*Qo/xd
} IOEM[zhb$
`fS^ j-_M
A';QuWdT
} P}r)wAt
\Tm}mAvK/o
J(iV0LAZb
/* 91d },Mq:
**SiteInfoBean.java m,tXE%l
*/ 9UD @MA
package NetFox; NQLiWz-q
"JT;gaEm
4/*q0M{}B
public class SiteInfoBean { [m2+9MMl
`X -<$x
-s"0/)HD
private String sSiteURL; //Site's URL p538r[f<
private String sFilePath; //Saved File's Path `ROG~0lN(
private String sFileName; //Saved File's Name h-XY4gq/
private int nSplitter; //Count of Splited Downloading File Mv|!2 [:
Ai kf|)D[
u"+}I,'L
public SiteInfoBean() (tCib 4
{//nSplitter的缺省值为5 %ROwr[Dj=
//default value of nSplitter is 5 @Icq1zb] y
this("","","",5); S; /. %
} (S9f/i^
.eF_cD7v
yrr) y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >^SEWZ_[
{ ' [p)N,
sSiteURL= sURL; \l,rpVv5m
sFilePath = sPath; a!,r46>$H
sFileName = sName; $3;Upgv
this.nSplitter = nSpiltter; f_\_9o"l
Ix8$njp[
z2 hFn&
} `_qK&&s
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<hvRP!~<)
public String getSSiteURL() J;QUPpHZ
{ P:{<*`q
return sSiteURL; 5<R%H{3j
} I.V:q!4*
K-Mc6
i[nF.I5*f
public void setSSiteURL(String value) <bUe/m
{ ejePDgi_[
sSiteURL = value; vq'k|_Qi=
} [EZYsOr.
$g\&5sstE
{1Eu7l-4
public String getSFilePath() wpo1
{ Q!'qC*Gyfn
return sFilePath; GDhM<bVqM*
} elO<a]hX
W>-B [5O&[
4na8
public void setSFilePath(String value) x]4Kkpqm
{ Gi?_ujZR
sFilePath = value; !@L=;1,
} f~h~5
(K{5fC
xvm5
public String getSFileName() h5~n 1qX
{ q31>uF
return sFileName; SreYJT%
} c$H+g,7xQ-
p]gT&[iJ
:E_a0!'
public void setSFileName(String value) j,-C{ K
{ 2}WDw>V
sFileName = value; {ERMGd6Jp
} 1=)r@X/6d
UT]?;o"
-4 Ux,9&
public int getNSplitter() "IjI'c
{ AHbZQulC
return nSplitter; mOBACTY^
} TwahR:T
Jfhk@27T
v/QUjXBr
public void setNSplitter(int nCount) nWYCh7
{ oh-|'5+,;h
nSplitter = nCount; &xd.Qi2
} smy}3k
} !!,0'c
L^J-("e_
Y "jE'
/* .zj0Jy8N
**Utility.java E4%j.
*/ [ !%R#+o=F
package NetFox; u'5`[U -!
2Aq~D@,9=:
N/F$bv
public class Utility { h0|}TV^UJ
@4GA^h
][@F
public Utility() 5er@)p_
{ bud&R4+
.2:\:H~3
l]LxL
} 4ne5=YY*
9<1F[SS<s9
//线程睡眠 TJ_=1Y@z
public static void sleep(int nSecond) X`r*ob
{ V%ii3
try{ "M H6fF
Thread.sleep(nSecond); Qyh/ed/
} yW7'?
catch(Exception e) l|`^*%W@u6
{ Snw3`|Y~<
e.printStackTrace (); !u|Tu4G^
} MmoR~~*
} t%VDRZo7
]`o!1(GA
//日志 Ud%s^A-qS
public static void log(String sMsg) =\kMXB
{ oOU1{[
System.err.println(sMsg); %:9oDK
} Qst$S}n
^4Uw8-/9
X]j)+DX>
public static void log(int sMsg) A#@_V'a8
{ Ub$n |xn
System.err.println(sMsg); ,J=P,](
} hwnJE958L
} YlK7;yrq(
]7GlO9
#@.-B,]
/* !X^Ce)1K
**TestMethod.java qa'gM@]
*/ PR7f(NC
package NetFox; >4i>C
1}m3;
IVvtX}
public class TestMethod { y0bq;(~X~
#=c`of6
^q[gxuL_
public TestMethod() `FF8ie8L
{ ///xx/weblogic60b2_win.exe D)b}f`
try{ pHE}ytcT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yc Q=vt{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M!m?#xz'c
SiteFileFetch fileFetch = new SiteFileFetch(bean); hlJpElYf
fileFetch.start(); P.\nLE J=
} wEft4o
catch(Exception e){e.printStackTrace ();} cWAtju?L;
~W0(1# i
\1%l^dE@
} k)\gWPH
,?cH"@RJ
7N8H)X
public static void main(String[] args) a|j%n
{ A&5:ATQ/|
new TestMethod(); 5N7H{vT_
} D/(CU#i"
} *#U+qgA;`
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