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)); `vjn,2S}
} )qSjI_qt5
for(int i=0;i<nEndPos.length-1;i++) `]~1pc
{ %#t*3[
nEndPos = nStartPos[i+1]; 9*~bAgkWI
} Y"H'BT!b}
nEndPos[nEndPos.length-1] = nFileLength; ^^,cnDlm
} gGZ-B<
} 5 EhOvt8
s>J\h
6-E>-9]'E
//启动子线程 7N:3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TOT#l6yqdd
for(int i=0;i<nStartPos.length;i++) M( w'TE@
{ nA*Udrcn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4y*"w*L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '+EtnWHs
nStartPos,nEndPos,i); (aC~0 #4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `D/<*e,#
fileSplitterFetch.start(); W&~\@j]!D
} H!'Ek[s+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ycq+C8J+Ep
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qu\cU(H|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @7HHi~1JK
nEndPos = " + nFileLength); =kzuU1s
// fileSplitterFetch[nPos.length-1].start(); G&Fe2&5!w
>\br8=R
-7Bg5{FA
//等待子线程结束 [KQ#b
//int count = 0; MO^Q 8v
//是否结束while循环 X9 N4
boolean breakWhile = false; 3</W}]$)p
MJ"@
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while(!bStop) VLPPEV-u
{ 2Tp@;[!3
write_nPos(); gmqA 5W~y
Utility.sleep(500); &]"Z x0t5%
breakWhile = true; _C@A>]GT
LZtO Q__B)
&|-jU+r}B
for(int i=0;i<nStartPos.length;i++) |LV}kG(2
{ *I:a\o~$[
if(!fileSplitterFetch.bDownOver) )\KU:_l
{ FuC#w 9_
breakWhile = false; mzf~qV^T
break; "D,}|
} &=*sN`
} R$h B9BK
if(breakWhile) +~K) ~
break; )O],$\u
EtnuEU
l{I.l
//count++; 3/N~`!zeX
//if(count>4) IM$ d~C
// siteStop(); BUCPO}I
} '4Drs}j5
P3!JA)p6a
s6F0&L;N&
System.err.println("文件下载结束！"); M3U?\g
} (`&SV$m
catch(Exception e){e.printStackTrace ();} hG~HV{6
} *Sg6VGP
){LU>MW{&
::p%R@?
//获得文件长度 QE|x[?7e,!
public long getFileSize() 7@R^B=pb
{ B&QEt[=s
int nFileLength = -1; 6&+}Hhe
try{ ;Q8`5h
URL url = new URL(siteInfoBean.getSSiteURL()); i>7]9gBm1q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X2|&\G9c
httpConnection.setRequestProperty("User-Agent","NetFox"); \3&1iA9=)
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iCJXV'
int responseCode=httpConnection.getResponseCode(); llN/
if(responseCode>=400) x4i&;SP0
{ \kZ@2.pN
processErrorCode(responseCode); $."DOZQ3U
return -2; //-2 represent access is error pocXQEg$]
} XU<XK9EA
Y[N@ )E_G
6u'E}hAx|
String sHeader; B)*1[Jf{4
:9DyABK=Cv
J`4V\D}n
for(int i=1;;i++) ?bH`
{ bE,#,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :N!s@6
//Utility.log(in.readLine()); =Fc}T%
sHeader=httpConnection.getHeaderFieldKey(i); q[Tl#*P?y
if(sHeader!=null) :-_"[:t 5Z
{ -_xTs(;|8
if(sHeader.equals("Content-Length")) [!C!R$AMa
{ |No9eZ8>.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4p7j"d5
break; :IX,mDO
} o5['5?i}/
} ;eJ|)*
else :%gM Xsb
break; $ y(Qdb
} _FNW[V
} OHwH(}H?
catch(IOException e){e.printStackTrace ();} d}aMdIF!e
catch(Exception e){e.printStackTrace ();} G6}!PEwM
7~r_nP_
<Mndr8 H
Utility.log(nFileLength); I s|_
~z^49Ys:
1+"d-`'Z2O
return nFileLength; qpQiMiB#g'
} X(O:y^sX}
.}GOHW)}
]4/C19Fe!
//保存下载信息（文件指针位置） ._]*Y`5)d
private void write_nPos() '0^lMQMg
{ /U,(u9bq
try{ B}P!WRNmln
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1Vkb}A,'
output.writeInt(nStartPos.length); [wk1p-hf
for(int i=0;i<nStartPos.length;i++) Y3#8]Z_"}O
{ W9{i~.zo
// output.writeLong(nPos); :]4s;q:m
output.writeLong(fileSplitterFetch.nStartPos); IAWs}xIly
output.writeLong(fileSplitterFetch.nEndPos); k&M~yb
} \PD%=~
output.close(); ?VCp_Ji
} @HTs.4
catch(IOException e){e.printStackTrace ();} /eT9W[a
catch(Exception e){e.printStackTrace ();} *ZV3]ig2$
} .AQTUd(_
/3.;sS]B
7yJE+o'
//读取保存的下载信息（文件指针位置） l*(L"]
private void read_nPos() BUdO:fr
{ ^hsr/|
try{ G*=&yx."E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jd2 p~W
int nCount = input.readInt(); ]N,'3`&::
nStartPos = new long[nCount]; "!& o|!2
nEndPos = new long[nCount]; 5R)IL2~
for(int i=0;i<nStartPos.length;i++) 7Le-f
{ P8#_E{f
nStartPos = input.readLong(); \[|X^8j
nEndPos = input.readLong(); TD-B\ @_
} P)LQ=b}V#;
input.close(); ;pS+S0U
} ?&!!(dWFH
catch(IOException e){e.printStackTrace ();} qJJ 5o?'
catch(Exception e){e.printStackTrace ();} A k~|r#@
} )y6
}O+S}Hbwy
:#\jx
private void processErrorCode(int nErrorCode) <pXOE-G5
{ 1;+77<
System.err.println("Error Code : " + nErrorCode); g6xQQ,q=l
} 4=%,0.yt
{t4':{Y+
O2"@09:
//停止文件下载 WZjR^6
public void siteStop() lYS "
{ @Z7s3b
bStop = true; vXZP>
for(int i=0;i<nStartPos.length;i++) ?%%vQ?
fileSplitterFetch.splitterStop(); P8H2v_)X&
SmRFxqtN
B qINU
} w11L@t[5W8
} O>I%O^
//负责部分文件的抓取 +3M1^:
**FileSplitterFetch.java a^^OI|?
*/ {u0sbb(
package NetFox; @\:@_}Z`_}
S;/pm$?/
:^qUr`)
import java.io.*; tR4+]K
import java.net.*; %{UW!/
zo8&(XS
oLtzPC
public class FileSplitterFetch extends Thread { [S-#}C?~
/XA*:8~!
9xK#(M
String sURL; //File URL 4#t=%}
long nStartPos; //File Snippet Start Position AFeFH.G6Jr
long nEndPos; //File Snippet End Position I~E&::,
int nThreadID; //Thread's ID |Om9(xT
boolean bDownOver = false; //Downing is over D><^7nr%
boolean bStop = false; //Stop identical X{[$4\di{
FileAccessI fileAccessI = null; //File Access interface ug'^$geM
E(z|LS*3
kpy)kS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |Bv,*7i&
{ EP90E^v^
this.sURL = sURL; Nx+5rp
this.nStartPos = nStart; /Z~$`!J
this.nEndPos = nEnd; EMxMJ=
nThreadID = id; #)i+'L8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ' QjJ^3A
} XWX]/j2jA
DwK$c^2q{.
{$pi};
public void run() ,1.Td=lY$
{ w_;$ahsu~
while(nStartPos < nEndPos && !bStop) &os:h] C
{ 5|`./+Ghk
mVN\
(dy:d^
try{ `,Y3(=3Xe?
URL url = new URL(sURL); R:ecLbC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \IEuu^
httpConnection.setRequestProperty("User-Agent","NetFox"); JV8*;n%}-
String sProperty = "bytes="+nStartPos+"-"; g&Uu~;jq]
httpConnection.setRequestProperty("RANGE",sProperty); g $^Yv4
Utility.log(sProperty); l>hvWK[ ?I
'#oH1$W]
*.VNyay
InputStream input = httpConnection.getInputStream(); 2S4SG\
//logResponseHead(httpConnection); `Tk~?aY
t!u>l
dB QCr{7
byte[] b = new byte[1024]; )c 79&S
int nRead; epG =)gd=8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 16nU`TN
{ +D[C.is>]}
nStartPos += fileAccessI.write(b,0,nRead); 5`lVC$cP
//if(nThreadID == 1) eLV[U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ytb1hFs
} B?e] Ht
r%>7n,+o
K(?p]wh
Utility.log("Thread " + nThreadID + " is over!"); kbbHa_;aqV
bDownOver = true; @3U=kO(^+\
//nPos = fileAccessI.write (b,0,nRead); ?k@;,l :s
} gNkBHwv
catch(Exception e){e.printStackTrace ();} w4&\-S#
} b`}hw"f
} FBOgaI83G
x2/ciC
0Pt%(^
//打印回应的头信息 (h[. Ie
public void logResponseHead(HttpURLConnection con) cK\?wZ| Y
{ e5"5 U7
for(int i=1;;i++) H|MAbx 7
{ b&d4(dk
String header=con.getHeaderFieldKey(i); *iyc,f^w
if(header!=null) jR+kx:+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NSR][h_
Utility.log(header+" : "+con.getHeaderField(header)); cFq2 6(e
else \JCpwNT{P
break; H =&K_
} 10GU2a$0"$
} gO@LJ
M6V^ur 1
Kw:%B|B<T
public void splitterStop() /1bQ RI^\
{ 5Q8s{WQ
bStop = true; C}pQFL{B5
} ;<%th
Ysw&J}6e
g&8-X?^Q
} ZXIz.GFy+
",Fvv
Sogt?]HB$
/* ^V]IPGV
**FileAccess.java A^zd:h-
*//文件访问(定位，写) Mp[2Auf
package NetFox; e)87 & 7
import java.io.*; YOA)paq+
}gE^HH'
k 6i&NG6
public class FileAccessI implements Serializable{ QNxxW2+
[8Z !dj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ht]O:io`
RandomAccessFile oSavedFile; 5v=e(Ph+
long nPos; @Q&k6.{4Z
e nw*[D !
g+(Y)9h&
public FileAccessI() throws IOException &^Gp
{ F%O+w;J4
this("",0); <,U$Y>
} mHH>qW{`
.*J /F$
f9)0OHa
public FileAccessI(String sName,long nPos) throws IOException a(G}<
{ `lt[Q>Z
oSavedFile = new RandomAccessFile(sName,"rw"); : JSuC
this.nPos = nPos; kE[R9RS!
oSavedFile.seek(nPos); WYkh'sv >
} PY&mLux%
A!}Ps"Z
i|28:FJA
public synchronized int write(byte[] b,int nStart,int nLen) +c__U Qx
{ 2lqy<o
int n = -1; ),^pi?
try{ b&AeIU}&
oSavedFile.write(b,nStart,nLen); vkeZ!klYB
n = nLen; o1-_BlZ
} +Y$EZL.A
catch(IOException e) IA`Lp3Z
{ SDs#w
e.printStackTrace (); nUisC5HW
} FJT0lC
%'S[f
>&^jKfY
return n; @3S:W2k
} SzfMQ@~
_sY; dS/
&)_ z!
} 1y,/|Y
}d5~w[
O]Yz7
/* \l`{u)V
**SiteInfoBean.java H?V b
*/ 6)>otB8)J
package NetFox; ofPv?_@
y! QYdf?
,R-aO= %
public class SiteInfoBean { s=556
Py?Q::
iJCv+p_f
private String sSiteURL; //Site's URL =hY/Yr%P
private String sFilePath; //Saved File's Path 4U u`1gtz
private String sFileName; //Saved File's Name 2^f7GP
private int nSplitter; //Count of Splited Downloading File )CgH|z:=b
Ka<J* k3
<Pi#-r.,
public SiteInfoBean() .1_kRy2*.
{//nSplitter的缺省值为5 \^jRMIM==
//default value of nSplitter is 5 wyXQP+9G
this("","","",5); jdx T662q
} ~=|QPO(d
J93xxj
1xSG(!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x0)WrDb
{ r\)bN4-g
sSiteURL= sURL; C;.,+(G
sFilePath = sPath; <;Tr
sFileName = sName; Z#YNL-x
this.nSplitter = nSpiltter; $+$l?2
p+dOw#
(%"9LYv
} {faIyKtW
M+:9U&>
)ybF@emc
public String getSSiteURL() 2. v<pqn
{ >`0mn|+
return sSiteURL; HV*;Yt
} 8pZOgh
bR8`Y(=F9b
NOKU2d4 G
public void setSSiteURL(String value) yqB!0) <
{ xErb11
sSiteURL = value; ;uzLa%JQ
} E]=>@EX
J;4aghzY
8;#yXlf
public String getSFilePath() u(\O@5a
{ -Zp BYX5e_
return sFilePath; !SIk9~rJ
} sV\K[4HG
0?dr(
ia_lP
public void setSFilePath(String value) FYK`.>L28
{ W+5. lf=2>
sFilePath = value; 2U(qyC
} 0N$FIw2
UM<s#t`\3
^)(tO$S
public String getSFileName() ?Dn}
{ l@ (:Q!Sk
return sFileName; TwI'XMO;A
} qI${7
JYv<QsD
0%4OmLBT
public void setSFileName(String value) %%zlqd"0
{ e[0"x.gu
sFileName = value; `csZ*$7
} ga(k2Q;y
*ZxurbX#
q6<P\CSHy<
public int getNSplitter() SvrUXf
{ e`OQ6|.k8
return nSplitter; tw&v@HUP
} 5$+ssR_?k
iRbe$v&N
*>1^q9M
public void setNSplitter(int nCount) 0/9]TIc
{ QodWUbi'&
nSplitter = nCount; YPf?
} i'4.w?OZ
} R<(xWH
4 Tw~4b
>[;=c0(
/* $*T?}r>
**Utility.java C,GZ
*/ t,IOq[Vtk
package NetFox; 8ZLHN',
xV 2C4K
qZ&~&f|>e
public class Utility { v^vi *c
4d-(:
egURRC!
public Utility() #<ST.f@*
{ C/'w
44|tCB`
>]~|Nf/i
} }a.j~>rq
zn7)>cQ905
//线程睡眠 bI8uw|c
public static void sleep(int nSecond) ,isjiy J
{ %.?V\l
try{ /-G_0A2wF
Thread.sleep(nSecond); OZnKJ<
} eZN"t~\rX
catch(Exception e) "H<us?r{
{ k)|.<
e.printStackTrace (); ;i'[c`
} Z7RBJK7|.
} :GO"bsjL
Y[dq"
//日志 %dv?n#Uf
public static void log(String sMsg) M +r!63T
{ R&J?XQ
System.err.println(sMsg); 7.6L1srV
} ?s3S$Ih
(Bd'Pj]:
K +3=gBU*w
public static void log(int sMsg) O#^H.B
{ d]"4aS
System.err.println(sMsg); 0GXY2+p}S
} CgrQ"N5
} J}:.I>
lM{fld
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/* +38R#2JV
**TestMethod.java +E_yEH7_)
*/ {svo!pN:
package NetFox; mPk'a
/:'>-253
n2hV}t9O
public class TestMethod { >([,yMIY
3m`>D e
>MYDwH
public TestMethod() 9;?u%
{ ///xx/weblogic60b2_win.exe ~"CGur P
try{ Mjy:k|aY"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .8Bo5)q$a-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I4{xQI
SiteFileFetch fileFetch = new SiteFileFetch(bean); Cul=,;pkB
fileFetch.start(); q*3keB;X
} ;ryNfP%
catch(Exception e){e.printStackTrace ();} !NkCki"W
5$D"uAp<V
d#H9jg15e
} PD-&(ka.
b' y*\9Ru
q1( [mHZ
public static void main(String[] args) n]ba1t8ZA
{ '=n?^EPE3
new TestMethod(); g}xL7bTlI>
} Oo}h:3?
} pB8D
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