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)); 4%>+Wh[
} 'F<Sf:?.p
for(int i=0;i<nEndPos.length-1;i++) (l2<+R%1
{ gQ,4xTX
nEndPos = nStartPos[i+1]; ,L~snR'w
} >E~~7Yal
nEndPos[nEndPos.length-1] = nFileLength; g6`.qyVfz'
} oo'iwq-\
} |} 9GHjG
qAbd xd[
-rRz@Cr
//启动子线程 +ruj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ss+F9J
for(int i=0;i<nStartPos.length;i++) LiF.w:}
{ @M9_j{A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >!<V\ Fj1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0pCDEs
nStartPos,nEndPos,i); m9k2h1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pdy+h{]3
fileSplitterFetch.start(); $ JuLAqq
} }R\B.2#M_@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^[*AK_o_DQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #e*$2+`[A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8W{ g
nEndPos = " + nFileLength); Hj1k-Bs&'w
// fileSplitterFetch[nPos.length-1].start(); W >Kp\tD
s7AI:Zv
nT)~w s
//等待子线程结束 BHIM'24bp
//int count = 0; 8@Q"YA3d+
//是否结束while循环 vevx|<9,
boolean breakWhile = false; ?SB5b,
'2j~WUEmg
sgR 9d
while(!bStop) zEAx:6`c
{ : qr}M
write_nPos(); @!Y.935/0
Utility.sleep(500); sAf9rZt*'
breakWhile = true; ]KzJ u`O%G
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for(int i=0;i<nStartPos.length;i++) [10$a(g\x
{ x9TuweG
if(!fileSplitterFetch.bDownOver) cFe V?a
{ YqkA&qL]#;
breakWhile = false; @RQ+JYQi
break; .!9Vt#
} eO~eu]r
} zCyR<as7
if(breakWhile) vxF:vI# @
break; xMLrLXy
bW}b<(y
ya;@<b
//count++; &qG?[R{
//if(count>4) |YJ$c@
// siteStop(); {P,>Q4N
} aS2a_!f
8U8P g2
_3*: y/M_
System.err.println("文件下载结束！"); e_tZja2s
} oM-b96
catch(Exception e){e.printStackTrace ();} 8a_ UxB
} c,+iU R<
/abmjV0
USH@:c#t
//获得文件长度 }3LBbG0Bw
public long getFileSize() +0pgq (
{ %-T}s`Z
int nFileLength = -1; lK_ ~d_f
try{ '3IkPy1Uz
URL url = new URL(siteInfoBean.getSSiteURL()); oD Q9.t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zjw!In|vC
httpConnection.setRequestProperty("User-Agent","NetFox"); jt0H5-x
pW`ntE#L
W` WLW8Qsw
int responseCode=httpConnection.getResponseCode(); &E} I
if(responseCode>=400) `8.1&fBr
{ IY-(- a8
processErrorCode(responseCode); F0X5dv
return -2; //-2 represent access is error "v*oga%
} ^U R-#WaQ
>aNbp
B:B0p+$I
String sHeader; "TEBByO'
W9:fKP
JS }_q1H
for(int i=1;;i++) @2)t#~Wc4h
{ m T>b;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q}wl_ku9+
//Utility.log(in.readLine()); gK&5HTo
sHeader=httpConnection.getHeaderFieldKey(i); zZS>+O
if(sHeader!=null) J r=REa0
{ UUt~W
if(sHeader.equals("Content-Length")) ZJiuj!
{ <L[T'ZE+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yBUZVqqDa
break; r@N39O*Wq
} Q"x`+?!
} L{+&z7M
else 0(Yh~{
break; oAIY=z
} )*q7pO\cty
} &<\4q
catch(IOException e){e.printStackTrace ();} t?pIE cl
catch(Exception e){e.printStackTrace ();} B<vvsp\X
!Qj)tS#Az
OqAh4qa,$
Utility.log(nFileLength); m70`{-O
hg<"Yg=
yf0vR%,\
return nFileLength; E#IiyZ
} N>W;0u!
4i ~eTb
#`fi2K&]j
//保存下载信息（文件指针位置） ~z-?rW
private void write_nPos() `8$:F4%P
{ __oY:d(~
try{ 9b"}CEw
output = new DataOutputStream(new FileOutputStream(tmpFile)); }.fZy&_
output.writeInt(nStartPos.length); "t3uW6&
for(int i=0;i<nStartPos.length;i++) tal>b]B;
{ D;16}D
// output.writeLong(nPos); p 02nd.R6
output.writeLong(fileSplitterFetch.nStartPos); f}evw K[S
output.writeLong(fileSplitterFetch.nEndPos); UBUB/NY
} ^VM"!O;h{
output.close(); o>/uW8
} :8\*)"^E
catch(IOException e){e.printStackTrace ();} 1[fkXO{
catch(Exception e){e.printStackTrace ();} -+j9X;h:
} KNO*)\
/r::68_KQP
sK""
//读取保存的下载信息（文件指针位置） 'PmHBQvt&
private void read_nPos() tS_xa
{ bv:0EdVr
try{ Xy3g(x]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y%n{`9=
int nCount = input.readInt(); )sqp7["-
nStartPos = new long[nCount]; S\yu%=h
nEndPos = new long[nCount]; \S|VkPv
for(int i=0;i<nStartPos.length;i++) df21t^0/
{ ~:ub
nStartPos = input.readLong(); U#UVenp@
nEndPos = input.readLong(); ]*kP>
} pUCEYR
input.close(); ^^t]vojX
} X$j|/))
catch(IOException e){e.printStackTrace ();} MIk #60Ab
catch(Exception e){e.printStackTrace ();} |)|vG_
} cAsSN.HFS
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rS,*s'G
private void processErrorCode(int nErrorCode) (F4dFh
{ wHo#%Y,Nmi
System.err.println("Error Code : " + nErrorCode); vMW-gk
} ~8Dd<4?F]
M;S-ESQ
U&d-?PI
//停止文件下载 sTYuwna~
public void siteStop() U:etcnb4w>
{ (|ct`KU0#
bStop = true; lyOrM7Gs
for(int i=0;i<nStartPos.length;i++) y<'2BTf
fileSplitterFetch.splitterStop(); bSeL"
$Nt]${0
{$u@6& B
} gs`27Gih
} btB(n<G2#
//负责部分文件的抓取 .H[Lo>
**FileSplitterFetch.java Ue>A
*/ g[D,\
package NetFox; VQG /g\
'%eaK_+7
^}Dv$\;6
import java.io.*; ~NxoF
import java.net.*; $+)x)1
{_k!!p6
1VPN#Q!
public class FileSplitterFetch extends Thread { Tg{dIh.Q~O
n)wpxR
i+T0}M<
String sURL; //File URL kHo;9j-U
long nStartPos; //File Snippet Start Position o}AqNw60v
long nEndPos; //File Snippet End Position 2!~>)N
int nThreadID; //Thread's ID ]>S$R&a
boolean bDownOver = false; //Downing is over _+R_ms
boolean bStop = false; //Stop identical zM9).D H
FileAccessI fileAccessI = null; //File Access interface 644hQW&W
AIRVvW~($
:'^dy%&UB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +2k|g2
{ D.oS8'
this.sURL = sURL; ?XTg%U
this.nStartPos = nStart; |]2eGrGj4
this.nEndPos = nEnd; 3Oig/KZ
nThreadID = id; 2}xFv2X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |Z^c#R
} s_Ge22BZ
1+PNy d
gp|7{}Q{
public void run() _>:=<xyOq
{ }mT%N eS
while(nStartPos < nEndPos && !bStop) aBA#\eV
{ oRJP5Y5na
(1r>50Ge
[2H(yLwO
try{ *v7& T
URL url = new URL(sURL); 4[f7X4d$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pi]s<3PL
httpConnection.setRequestProperty("User-Agent","NetFox"); J!^~KN6[
String sProperty = "bytes="+nStartPos+"-"; OD@@O9
httpConnection.setRequestProperty("RANGE",sProperty); scPq\Qd?O
Utility.log(sProperty); %&Q7;?
w$_'xX(
E*!zJ,@8
InputStream input = httpConnection.getInputStream(); 77=y!SDP
//logResponseHead(httpConnection); C6=;(=?C
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XtH_+W+O
byte[] b = new byte[1024]; +/_B/[e<>
int nRead; z&HN>7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zn*CJNB
{ $nd-[xV
nStartPos += fileAccessI.write(b,0,nRead); ~PS2[5yo
//if(nThreadID == 1) cI4qgV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z=/L6Zb
} gJ[q {b
'r?HL;,q
MFdFZkpiV
Utility.log("Thread " + nThreadID + " is over!"); kk\zZC <
bDownOver = true; 9Nbg@5(
//nPos = fileAccessI.write (b,0,nRead); TAXkfj
} Vwh&^{Eh
catch(Exception e){e.printStackTrace ();} qu~"C,
} LXEu^F~{u#
} p$!+2=)gY
s"Pk-Dv
,tv9+n@x
//打印回应的头信息 Ai_|)
public void logResponseHead(HttpURLConnection con) q!h*3mNm
{ )b2E/G@X&
for(int i=1;;i++) hu*>B
{ %IH|zSr)EM
String header=con.getHeaderFieldKey(i); 9oau_Q#
if(header!=null) )1yUV*6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D!E 9@*Lf
Utility.log(header+" : "+con.getHeaderField(header)); ]B.,7
else .gsu_N_v
break; KL\=:iWA
} "E[*rnsLN
} n YMf[kW
Cq;K,B9
<IkD=X
public void splitterStop() rpP+20v
{ hs#s $})}Z
bStop = true; 0~L8yMM
} U!UX"r
qxCL
2dJ)4
} .1q~,}toX
3/|{>7]1
% |Gzht\
/* X|lmH{kf
**FileAccess.java \U =>
*//文件访问(定位，写) X%\6V;zR#
package NetFox; B46H@]d#7K
import java.io.*; uXW. (x7"f
i$<v*$.o
~322dG
public class FileAccessI implements Serializable{ SE-, 1p
H.G^!0j;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ia.B@u1/
RandomAccessFile oSavedFile; [&}<!:9'
long nPos; ;%.k}R%O@
|q b92|?
?|rw=%
public FileAccessI() throws IOException Gg,k
{ ,7nb;$]
this("",0); *E q7r>[
} 3K]0sr
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GM56xZ!2T
public FileAccessI(String sName,long nPos) throws IOException art{PV4-
{ cF6|IlhO
oSavedFile = new RandomAccessFile(sName,"rw"); ,P}c92;
this.nPos = nPos; |($pXVLH`
oSavedFile.seek(nPos); P]n 'q
} (rJvE*
&kG<LGXP#
U:Y?2$#
public synchronized int write(byte[] b,int nStart,int nLen) t`Sh!e
{ !duR7a
int n = -1; )l=j,4nn
try{ zy|hf<V
oSavedFile.write(b,nStart,nLen); .NKN2
n = nLen; mS0W@#|K
} ,f$RE6
catch(IOException e) >2a~hW|,
{ LE;c+(CAU
e.printStackTrace (); ?g'l/xuRe
} {}z7N~
_xJ&p$&
6vDgMfw
return n; >_@J&vC
} (f)QEho7
}5K\l
;/v^@
} 5q\]]LV>
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%:NI@59
/* #u~8Txt
**SiteInfoBean.java aa|xZ
*/ OA_ %%A;o
package NetFox; E:2Or~
F J)la9
dQ<EDtap
public class SiteInfoBean { RW'QU`N[Y
"zugnim
},l3N K
private String sSiteURL; //Site's URL (UCWSA7oc
private String sFilePath; //Saved File's Path NOvN8.K%
private String sFileName; //Saved File's Name (uSfr]89'
private int nSplitter; //Count of Splited Downloading File +S$x}b'5q
8"+Kz
5( 3tPbm{
public SiteInfoBean() z;T?2~g!
{//nSplitter的缺省值为5 [L:,A{rve
//default value of nSplitter is 5 =oBV.BST u
this("","","",5); tlj^0
} ]'hz+V31%
`On%1%k8
OF}vY0oiw?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b^0=X!bg
{ 8< R#}
sSiteURL= sURL; n;[d{bU
sFilePath = sPath; o<Q~pd#Ip,
sFileName = sName; &4LrV+`$V
this.nSplitter = nSpiltter; d-X<+&VZ
^]K_k7`I
MFRM M%`
} 3>ytpXUEGx
3:s!0ty"
{>9vm!<[*\
public String getSSiteURL() !Eu}ro.}
{ NbH;@R)L
return sSiteURL; >o.4sN@
} nwf(`=TC
W2'u]1bs
`ml
public void setSSiteURL(String value) 13kl\<6
{ }Ge$?ZFH
sSiteURL = value; UZz/v#y~
} ';Y0qitGB
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@kd`9Yw
public String getSFilePath() Pd)mLs Jg
{ PKJw%.-
return sFilePath; wt]onve}%
} KSz;D+L\
I;FHjnn(
VX0}x+LJ
public void setSFilePath(String value) g=n{G@*N
{ Q\rf J||
sFilePath = value; H}?"2jF
} ]lqLC
qz95)
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public String getSFileName() zcGmru|k
{ 6+!$x?5|NP
return sFileName; _0}u0fk
} 4K5
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Z-:T')#Cf
public void setSFileName(String value) y*=sboX
{ OYSq)!:
sFileName = value; V/`vX;%
} fJOwE g|
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L>LIN 1A
public int getNSplitter() !#d5hjoX
{ ml@;ngmp.
return nSplitter; t'1g+g
} fqjBor}
(\ge7sE-oo
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public void setNSplitter(int nCount) E5!vw@,
{ j"K^zh
nSplitter = nCount; By waD?
} KRz~3yH{c
} oqAO@<dL!
Om^(CAp
9U8x&Z]P
/* 9 ,:#Q<UM
**Utility.java A'BqNsy
*/ 7Xx3s@
package NetFox; -0UR%R7q
793 15A
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public class Utility { ![;={d0
7HkFDI()1
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public Utility() QEg[
{ 6@TU9AZS`
").gPmC
SV@*[r
} 10fxK
(>vyWd]
//线程睡眠 )by7[I0v
public static void sleep(int nSecond) HdN5zl,q
{ )7 q"l3e"u
try{ Lo3N)~5
Thread.sleep(nSecond); Pr1qX5>=
} #B<EMGH
catch(Exception e) M^[;{p2uZ
{ Ie(i1?`A8
e.printStackTrace (); +@=V}IO
} 4^uSW&`;/
} 1l$2T y+ =
"h#R>3I1)
//日志 *#'j0;2F
public static void log(String sMsg) g!R7CRt%
{ .6P.r}
System.err.println(sMsg); :~ pGHl
} &EqLF
Vf;&z$D{r
[a04( 2g
public static void log(int sMsg) N2O *g`YC
{ d!E_EoOi
System.err.println(sMsg); l3sF/zkH
} EW|$qLg
} &J)<1!|
'|DW#l\n
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/* &cL1 EQ(
**TestMethod.java aOH|[
*/ F%h3?"s
package NetFox; 6@s!J8!
>E>yA d
C3}:DIn"w
public class TestMethod { ?qNU*d
#B;P4n3
%"0,o$
public TestMethod() Z^_qXerjP
{ ///xx/weblogic60b2_win.exe T&lgWOls
try{ $Z:O&sD{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dymq Z<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UDHWl_%L
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4yxQq7 m,
fileFetch.start(); _#u\ar)
} K6kz{R%`
catch(Exception e){e.printStackTrace ();} 3>KEl^1DB
riDb!oC
_~z oMdT!
} eX+36VG\
X:oOp=y]|
M]s\F(*ib
public static void main(String[] args) xqt?z n
{ k7^hcth
new TestMethod(); /'sv7hg+
} vqSpF6F q
} $-}&RW9
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