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)); -N*[f9EJB
} $6a9<&LP_
for(int i=0;i<nEndPos.length-1;i++) Gr\ ]6
{ A?H#bRAs
nEndPos = nStartPos[i+1]; Hu"$)V
} 509T?\r
nEndPos[nEndPos.length-1] = nFileLength; ]SCHni_
} "[N2qJ}p
} +})QTFV
?4bYb]8Z
2g= 6s
//启动子线程 rGP;0KtQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G*I
for(int i=0;i<nStartPos.length;i++) s<zN`&t
{ lxyTh'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "V' r}>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &DWSf`:Hx
nStartPos,nEndPos,i); +]eG=. u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M-nRhso
fileSplitterFetch.start(); i1cd9
} 0vqVE]C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J\y^T3Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mD'nF1o Ly
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $|=|"/
nEndPos = " + nFileLength); ]lwf6'
// fileSplitterFetch[nPos.length-1].start(); +MX~1RU+
zR<{z
,`bW(V
//等待子线程结束 },8|9z#pyB
//int count = 0; NftnbsTmy
//是否结束while循环 "z{/*uM2<
boolean breakWhile = false; @P7'MiP]K
(%X *b.n=
1kvX#h&V
while(!bStop) FBXktSg
{ )/jDt dI
write_nPos(); gy}3ZA*F
Utility.sleep(500); cy8>M))c
breakWhile = true; dHDtY$/_
3gUY13C}:p
V *@q< rQ
for(int i=0;i<nStartPos.length;i++) ^*}D*=>\
{ 7Mh'x:p
if(!fileSplitterFetch.bDownOver) 28"1ONs3
{ VZi1b0k1.
breakWhile = false; p& _Z}Wv
break; JTKS5r7?
} 05 6K)E
} =`3r'c
if(breakWhile) l ms^|?
break; i{fw?))+
=MqEbQn{C3
D`p2aeI
//count++; RnkV)ed(
//if(count>4) nX!%9x$3
// siteStop(); hl:Ba2_E +
} 4mDHAR%D
`j{3|C=
16AlmegDk
System.err.println("文件下载结束！"); > SZ95@Oh
} ;5/Se"Nd
catch(Exception e){e.printStackTrace ();} mfj{_fR3
} SD^::bH
c,r6+oX
nOPB*{r|
//获得文件长度 =78y*`L
public long getFileSize() .4a|^ vT
{ QT%`=b
int nFileLength = -1; Z?eTjkNS#
try{ NOTG|\{
URL url = new URL(siteInfoBean.getSSiteURL()); -U2Su|:\N8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (]q ([e
httpConnection.setRequestProperty("User-Agent","NetFox"); <#:iltO
oO tjG3B({
&E]) sJ0
int responseCode=httpConnection.getResponseCode(); ;-1KPDIp`
if(responseCode>=400) dzIBdth
{ s]m]b#1!r
processErrorCode(responseCode); %72# tY
return -2; //-2 represent access is error (Iv@SiZf(
} ~aotV1"D
#X)DFAtb
()|e xWW
String sHeader; pss')YP.
UT@Qo}:
F[coa5
for(int i=1;;i++) 4M"'B A<
{ 7oE:]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j/Kul}Ml\*
//Utility.log(in.readLine()); #sU>L=
sHeader=httpConnection.getHeaderFieldKey(i); w?D=
if(sHeader!=null) A@3'I ;
{ 'cCM[P+
if(sHeader.equals("Content-Length")) ar@,SKU'K
{ Z84w9y7O<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MTwzL<@$
break; b|87=1^m[
} 9+(b7L
} %{ U (y#
else ]fY:+Ru
break; :LuA6
} &v]xYb)+<
} 6<z#*`U1
catch(IOException e){e.printStackTrace ();} jXx~5
catch(Exception e){e.printStackTrace ();} /\fR6|tJ
sB0]lj-[Un
fbI5!i#lz
Utility.log(nFileLength); iw.F8[})
"U9e)a0v
~e|E5[-i
return nFileLength; <YCjo[(~
} h/5V~ :)
ZXhNn<
vmxS^_I
//保存下载信息（文件指针位置） ^E, #}cW
private void write_nPos() l )r^|9{
{ 0]ai*\,W7~
try{ sfVzVS[
output = new DataOutputStream(new FileOutputStream(tmpFile)); `_&vvJPn@!
output.writeInt(nStartPos.length); 1&h\\&ic
for(int i=0;i<nStartPos.length;i++) nVpDjUpN
{ wI7.M Gt
// output.writeLong(nPos); yTc&C)Jba
output.writeLong(fileSplitterFetch.nStartPos); HZ(giAyjq
output.writeLong(fileSplitterFetch.nEndPos); a"cw%L
} {dh@|BzsbH
output.close(); Wu,=jL3?$A
} 8I*yS#
catch(IOException e){e.printStackTrace ();} WG3_(mM
catch(Exception e){e.printStackTrace ();} [g==#[
} :EPe,v RT
pl}W|kW}
BD$Lf,_
//读取保存的下载信息（文件指针位置） DW,Z})9
private void read_nPos() s&%r?
{ k-4z2qB
try{ Yi-,Pb?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 87pu\(,'
int nCount = input.readInt(); p*jH5h cy
nStartPos = new long[nCount]; C\[:{d
nEndPos = new long[nCount]; #.FhN x
for(int i=0;i<nStartPos.length;i++) (Rs;+S
{ &/Gf@[
nStartPos = input.readLong(); 9r:|u:i7m
nEndPos = input.readLong(); \1u^?cBd
} RSeav
input.close(); W T @XHwt
} 4U$M0 =
catch(IOException e){e.printStackTrace ();} a U<+ `
catch(Exception e){e.printStackTrace ();} h5vetci/
} 9qq6P!
ra ,.vJuT
jJ RaY3
private void processErrorCode(int nErrorCode) B&(/,.
{ 6EY0Fjsi
System.err.println("Error Code : " + nErrorCode); nBd(pOe
} 'K23oQwDB
k/Urz*O
B0g?!.#23
//停止文件下载 2Z9ck|L>
public void siteStop() U[pR`u
{ HKC&grp
bStop = true; Wa!C2nB
for(int i=0;i<nStartPos.length;i++) `OZiN;*|
fileSplitterFetch.splitterStop(); (s+}l?
fDXTedrG/
e ?Jgk$"
} d_[zt)
} &?j\=%
//负责部分文件的抓取 M?m@o1\;W
**FileSplitterFetch.java oB<!U%BN
*/ &`'@}o>2
package NetFox; u7&5t
7 /"Z/^
-23sm~`
import java.io.*; dM -<aq
import java.net.*; eS%8WmCV9<
&j"_hFhv
##" Hui
public class FileSplitterFetch extends Thread { pCeCR
I,/E.cRV<
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String sURL; //File URL y?iW^>|?L=
long nStartPos; //File Snippet Start Position fndH]Yp
long nEndPos; //File Snippet End Position Rd@?2)Xm
int nThreadID; //Thread's ID p8iKZI]g
boolean bDownOver = false; //Downing is over JGYJ;j{E]
boolean bStop = false; //Stop identical ayg^js2,
FileAccessI fileAccessI = null; //File Access interface V>4v6)N
8y4t9V
5p7i9"tgn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KO))2GET
{ ]~pM;6Pu0
this.sURL = sURL; 5IRUG)Icr
this.nStartPos = nStart; DnCIfda2g
this.nEndPos = nEnd; ;|,*zD
nThreadID = id; !W b Q9o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6anH#=(
} y=}o|/5"
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public void run() FW4#/H
{ rj29$d?Y9
while(nStartPos < nEndPos && !bStop) rLp0)Go
{ ~kI$8oAry
K;R!>p}t
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try{ cU"uKR
URL url = new URL(sURL); 5hDm[*83
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bW GMgC
httpConnection.setRequestProperty("User-Agent","NetFox"); Rf!$n7& \
String sProperty = "bytes="+nStartPos+"-"; mW3IR3b
httpConnection.setRequestProperty("RANGE",sProperty); =)!~t/
Utility.log(sProperty); !^aJS'aq
cmp@Ow"c
Vzh\1cF
InputStream input = httpConnection.getInputStream(); Ki[&DvW:
//logResponseHead(httpConnection); b~!Q3o'W
@n$/2y_.
2t3)$\ylQp
byte[] b = new byte[1024]; AD7&-=p&w
int nRead; 0>3Sn\gZ(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F ^)( 7}ph
{ -{p~sRc&
nStartPos += fileAccessI.write(b,0,nRead); 5[`f(;
//if(nThreadID == 1) *n9=Q9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e'3y^Vg
} K{iC'^wP
%\1W0%w
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Utility.log("Thread " + nThreadID + " is over!"); MVDy|i4
bDownOver = true; \ Ju7.3.
//nPos = fileAccessI.write (b,0,nRead); PSU}fo
} Bf$`Hf6
catch(Exception e){e.printStackTrace ();} wd2z=^S~
} T=[/x=
} u y13SkW
b%xG^jUXsX
,a":/ /[
//打印回应的头信息 D1wONss
public void logResponseHead(HttpURLConnection con) To,*H OP
{ Lr*\LP6jx3
for(int i=1;;i++) +6(\7?
{ wu0q.]
String header=con.getHeaderFieldKey(i); Bh65qHQO
if(header!=null) zCmx1Djz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O&@CT])8
Utility.log(header+" : "+con.getHeaderField(header)); ^(Wu$\SA
else O_v*,L!
break; PeJIa %iE
} #1p\\Av
} yg82a7D
]3L/8]:
ZQ_AqzT3D
public void splitterStop() QVkrhwp
{ $-paYQ4
bStop = true; h*\u0yD)
} V}Ce3wgvA
"-Wb[*U;
^`bMFsP
} %m-U:H.Vp
k\-h-0[|
\%&eDE0
/* aAgQ^LY
**FileAccess.java -[[(Zx
*//文件访问(定位，写) l\ VrD2j8
package NetFox; v4F+^0?
import java.io.*; P[tYu:
LHSbc!Y'.
9^@)R ED
public class FileAccessI implements Serializable{ (QQkXlJ
-s]@8VJA"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9T0g%&
RandomAccessFile oSavedFile; ,(NN)Oj
long nPos; 0B: v0R
-B?cF9
N! I$Qtr,
public FileAccessI() throws IOException R[OXYHu
{ MfO:BX@$
this("",0); BlqISyrY
} %^[D+1ULb
/O~Np|~v
B:Hr{%O
public FileAccessI(String sName,long nPos) throws IOException c:""&>Z
{ m~uT8R#$
oSavedFile = new RandomAccessFile(sName,"rw"); &^l(RBp]0
this.nPos = nPos; 13+.>
oSavedFile.seek(nPos); ^!gq_x
} fElFyOo+
1x%B`d
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public synchronized int write(byte[] b,int nStart,int nLen) n}c~+0`un
{ bAwKmk9C
int n = -1; egVKAR-
try{ (%mV,2|:20
oSavedFile.write(b,nStart,nLen); o7@C$R_#
n = nLen; zjOOEvi
} cQm4q19
catch(IOException e) K~B
{ Y=5P=wE
e.printStackTrace (); 3 FV -&Y
} u08QE,
h J0U-m
$tej~xZK
return n; %r8;i
} g/VV2^,
<y?=;54a
Ej1<T,w_
} T"<)B^8f
7Gy:T47T\@
'u~0rMe4})
/* |gIE$rt-~W
**SiteInfoBean.java hCS}
*/ 3#Bb4\_v
package NetFox; -:E~Z_J`
3R0ioi 7
eze%RjO}
public class SiteInfoBean { 2=/-,kOL_
zTc*1(^
Qj*.Z4ue
private String sSiteURL; //Site's URL xF@&wg
private String sFilePath; //Saved File's Path I Zw
private String sFileName; //Saved File's Name :q?#$?
private int nSplitter; //Count of Splited Downloading File e.~11bx
ncMzHw
&} { #g
public SiteInfoBean() um}q@BU
{//nSplitter的缺省值为5 &BRa5`
//default value of nSplitter is 5 |Wjpnz
this("","","",5); cnI5G!
} @bJIN]R
^39lUKL
,[)l>!0\H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~?FhQd\Q
{ gn&Zt}@[
sSiteURL= sURL; imeE&
sFilePath = sPath; 4QTHBT+2`
sFileName = sName; 0^sY>N"
this.nSplitter = nSpiltter; f 9Kt>2IN
%S'+x[4W
Fj]06~u
} q=Vh"]0g
ixSr*+
CS~_>bn
public String getSSiteURL() ~$J(it-a
{ ~UZ3 lN\E
return sSiteURL; &*%x]fQ@
} x~vNUyEN)
RB4 +"QUh
"RN] @p#m
public void setSSiteURL(String value) x7U=1y(
{ ^6z"@+;*
sSiteURL = value; N2"B\
} bd~m'cob>
kS8?N`2}LV
6(rN(C
public String getSFilePath() T7^;!;i`X
{ `Z8k#z'bN
return sFilePath; <|jh3Hlp
} }Sbk qd5
pCA`OP);=
IEMa/[n/
public void setSFilePath(String value) -v.\W y~\
{ &i(Ip'r
sFilePath = value; 5a$EXV
} 849,1n^
:C(/yg
#[bL9R5NC
public String getSFileName() }#7rg_O]>
{ yV )fJ_
return sFileName; 0hV#]`9`gN
} {;u,04OVK
OtmDZ.t;`
75zU,0"j
public void setSFileName(String value) V<J1.8H
{ [I3Nu8
sFileName = value; 5dI=;L>D
} J\Pb/9M/
oDMPYkpTu
XhHgXVVGG<
public int getNSplitter() OyF=G^w
{ R`Z"ey@C
return nSplitter; nOvR, 6
} _ERtL5^
G<n75!
Q(nTL WW
public void setNSplitter(int nCount) ]}XDDPbZ}
{ G rp{ .
nSplitter = nCount; >kK@tJn
} ZBK0`7#&EH
} Nw1*);b[y
8O9^g4?
+w^,!gA&
/* R~kO5jpW
**Utility.java in<.0v9w
*/ XGR2L DR
package NetFox; s@@Km1w
A-T-4I
Ee2P]4_d
public class Utility { "u!gfG?oH
dX cbS<
QQ.?A(U7
public Utility() <&l$xn
{ MmN{f~Kq9
#0aBQ+_8H
eTvWkpK+
} ;+E]F8G9r
'7sf)0\:<p
//线程睡眠 PJC(:R(j
public static void sleep(int nSecond) {MUiK5:
{ e"%TU
try{ gHBvQ1g
Thread.sleep(nSecond); vS>'LX
} ]O"f%
catch(Exception e) r6Yd"~ n
{ ly17FLJ].
e.printStackTrace (); k8+J7(_c
} hhy+bA}
} |VWT4*K
7sxX?u
//日志 g2|Myz)
public static void log(String sMsg) 6MT (k:
{ 0vm>*M*p
System.err.println(sMsg); ?n`m
} 3y}E*QE
q5SPyfE[
*=!e,
public static void log(int sMsg) noxJr/A]
{ eut2x7Z(c
System.err.println(sMsg); iQgg[ )
} 8@m$(I+
} eUA]OF@
>o?v[:u*
4f[%Bb
/* 1l$Ei,9
**TestMethod.java >9&31wA_
*/ u[b |QR=5
package NetFox; p@^G)x
\sAaVdZJH(
'ztOl`I5V
public class TestMethod { lI=<lmM0|/
0hemXvv1
5[ zN M
public TestMethod() M,]|L ch
{ ///xx/weblogic60b2_win.exe k."p&
try{ \~ D(ww
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WPL@v+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xak)YOLRV
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^HC6v;K
fileFetch.start(); 6eV#x%z@v'
} EnM
catch(Exception e){e.printStackTrace ();} .HS6DOQ
1D*=ZkA)
1|MRXK
} ]y0Y(
}<04\t?
'I]XX==_
public static void main(String[] args) )!"fUz$
{ |sZqqgZ-
new TestMethod(); p'K`K\X
} xqG<R5k>>
} ~lw9sm*2v2
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