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)); /o=,\kM
} p$A`qx<M_
for(int i=0;i<nEndPos.length-1;i++) 95CCje{o_
{ smt6).o
nEndPos = nStartPos[i+1]; jboQ)NxT!,
} M=aWL!nJ
nEndPos[nEndPos.length-1] = nFileLength; >J[Wd<~t
} B[rxV
} >o"3:/3
(G:K?o)
8FY/57.W
//启动子线程 OY/sCx+c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L?5OWVX!v
for(int i=0;i<nStartPos.length;i++) X[ o9^<
{ "x$RTuWA9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KGI0|Z]n~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7VwLyy
nStartPos,nEndPos,i); P"WnU'+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h.W;Dmf6]
fileSplitterFetch.start(); );.q:"
} ;qF#!Kb5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (~>L \]!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j!H\hj/]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `y!6(xI
nEndPos = " + nFileLength); _,2P4
// fileSplitterFetch[nPos.length-1].start(); Nl^{w'X0h
&G>EBKn\2`
@#%rTKD9F
//等待子线程结束 d#9"_{P
//int count = 0; y`EcBf
//是否结束while循环 Gv,0{DVX<
boolean breakWhile = false; ]'UO]i/
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c=T^)~$$
while(!bStop) o(/(`/
{ 3eg<)
write_nPos(); $I7/FZP
Utility.sleep(500); 3T3p[q4
breakWhile = true; {&Fh$H!
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S)0bu(a`Z,
for(int i=0;i<nStartPos.length;i++) t;@VsQ8
{ Y@S?0
if(!fileSplitterFetch.bDownOver) /WVnyz0
{ |WB<yA1
breakWhile = false; MKdBqnM(F
break; ZN2g(
} X]Emz"
} 3?vasL
if(breakWhile) QJ ueU%|
break; <~}t;ji
Ha\q}~_
!j)H!|R
//count++; w 1E}F
//if(count>4) IA|V^Wmt;
// siteStop(); pX]*&[X?
} {37DrSOa
S< <xlW
|*N.SS
System.err.println("文件下载结束！"); OjCT*qyU<
} +SmcZ^\OZ
catch(Exception e){e.printStackTrace ();} byv(:xk|'e
} HlB'yOHv!
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>,`/ z
//获得文件长度 Tv0|e'^
public long getFileSize() z+1#p.F$@
{ 'A,&9E{%1
int nFileLength = -1; R.R(|!w>
try{ .e2u)YqA
URL url = new URL(siteInfoBean.getSSiteURL()); ?rQMOJR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,sk;|OAI
httpConnection.setRequestProperty("User-Agent","NetFox"); '?5=j1
*0y+=,"QU
3R?7&oXvH
int responseCode=httpConnection.getResponseCode(); 5( lE$&
if(responseCode>=400) 9jiZtwRpk
{ AjaG.fa]k
processErrorCode(responseCode); aI|<t^X
return -2; //-2 represent access is error J! >HT'M
} )}?'1ciHI
&j/ WjZPF
+b]g;
String sHeader; 6:B[8otQ
cW,wN~
*&B*/HAN
for(int i=1;;i++) x!q$`zF\\
{ ,SJB3if
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .bvB8VOrW
//Utility.log(in.readLine()); $6:j3ZTXrt
sHeader=httpConnection.getHeaderFieldKey(i); ~fs{Ff'
if(sHeader!=null) f3-=?Z
{ @3[Z QF
if(sHeader.equals("Content-Length")) pCA(>(
{ r]km1SrS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A5Yfm.Jy
break; O!sZMGF$p
} /yIkHb^c
} /Z>#lMg\.
else :9c QK]O6
break; Mno4z/4{A
} xrO:Y!C?
} _U$d.B'*)z
catch(IOException e){e.printStackTrace ();} !O)Ruwy
catch(Exception e){e.printStackTrace ();} !$St=!
gyieSXz[
-zHJ#
Utility.log(nFileLength); D<}KTyG]
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5_M9T3
return nFileLength; CIQo2~G
} ZSYXUFz
c3!d4mC:
npz*4\4
//保存下载信息（文件指针位置） suaTXKjyk+
private void write_nPos() S8<O$^L^
{ mN_RB{g{
try{ ]m(Uv8/6
output = new DataOutputStream(new FileOutputStream(tmpFile)); (ui"vLk8PP
output.writeInt(nStartPos.length); Z KnEg2a
for(int i=0;i<nStartPos.length;i++) eUVE8pZl
{ F)lDK.
// output.writeLong(nPos); M'HmVg4'
output.writeLong(fileSplitterFetch.nStartPos); &~G>pvZ
output.writeLong(fileSplitterFetch.nEndPos); Eti;(>"@
} G(|ki9^@"9
output.close(); {DBgW},
} .5|wy<
catch(IOException e){e.printStackTrace ();} E@R7b(:*
catch(Exception e){e.printStackTrace ();} HlPf
} N(]6pG=
LwkZ(Tt
^{-J Y
//读取保存的下载信息（文件指针位置） +QuaQ% lA
private void read_nPos() P$Xig
{ k%/Z.4vQG
try{ qWtvo';3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5>"$95D
int nCount = input.readInt(); o{?s\)aBa
nStartPos = new long[nCount]; DK&J"0jz,
nEndPos = new long[nCount]; G*mk 19Z
for(int i=0;i<nStartPos.length;i++) {Aj}s3v
{ !tmY_[\
nStartPos = input.readLong(); QOEcp% 6I}
nEndPos = input.readLong(); xg/3*rL
} 6N:fq
input.close(); `K~300-hOb
} d"Hh9O}6
catch(IOException e){e.printStackTrace ();} Cz+>S3v M
catch(Exception e){e.printStackTrace ();} 7:R8QS9
} 8"LvkN/v^
:u`
QW|,_u5j
private void processErrorCode(int nErrorCode) vEvVT]g[V
{ l^%Ez?-:s
System.err.println("Error Code : " + nErrorCode); &2Q4{i
} tV9nC
SI*O#K=w
<E|i3\[p
//停止文件下载 :o&qJ%
public void siteStop() GG5wiN*2S
{ {XC# -3O
bStop = true; SQ]&nDd
for(int i=0;i<nStartPos.length;i++) vR3'B3y
fileSplitterFetch.splitterStop(); votv rZ=
cMsm[D{b
- ~T LI&[
} 7d]}BLpjWz
} :xm,Ok
//负责部分文件的抓取 ga?.7F
**FileSplitterFetch.java ,sn ?V~)
*/ BEx? bf@|]
package NetFox; dG'aJQw
weU'3nNN
>>Z.]
import java.io.*; PR|F-/o
import java.net.*; fDNiU"
z^T/kK3I
:&HrOdz
public class FileSplitterFetch extends Thread { _)yn6M'Dt
vXAO#'4tm%
6UG7lH!M
String sURL; //File URL 7MZBU~,r
long nStartPos; //File Snippet Start Position '0[D-jEr
long nEndPos; //File Snippet End Position E;*#fD~@
int nThreadID; //Thread's ID SHOg,#mV
boolean bDownOver = false; //Downing is over DFQp<Eq]7
boolean bStop = false; //Stop identical y9{KBM%h
FileAccessI fileAccessI = null; //File Access interface ?"N,do
btJ:Wt}
Waj6.PCFm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X&8&NkH
{ oa?bOm
this.sURL = sURL; <xKer<D %
this.nStartPos = nStart; ) kfA5xi[
this.nEndPos = nEnd; WId"2W3M
nThreadID = id; [ p$f)'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $d3al%Uo
} GF*8(2h2
X9K@mX
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public void run() 0D+[W5TB
{ F"1)y>2k
while(nStartPos < nEndPos && !bStop) P%A;EF~v
{ c3W9"
y4PR&^l?g
'c*Q/C;
try{ ~,WG284
URL url = new URL(sURL); eRKuy l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7xTgG!>v
httpConnection.setRequestProperty("User-Agent","NetFox"); o|YY,G=C
String sProperty = "bytes="+nStartPos+"-"; (/UW}$] h
httpConnection.setRequestProperty("RANGE",sProperty); Hm!ffqO_
Utility.log(sProperty); :hr% 6K7
dlmF?N|EC
y{ %2Q)
InputStream input = httpConnection.getInputStream(); u9ObFm$7
//logResponseHead(httpConnection); 0}C> e`<'
0+L:+S
S<#>g s4
byte[] b = new byte[1024]; {4J:t_<nKO
int nRead; zP$0B!9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IL;JdIa
{ kU{+@MA;
nStartPos += fileAccessI.write(b,0,nRead); @E;'Ffo
//if(nThreadID == 1) XP'<\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gBp,p\ Xc
} OJ^kESrm8
AiKja>Fl<
X|zQZ<CO
Utility.log("Thread " + nThreadID + " is over!"); Hof@,w
bDownOver = true; meey5}
//nPos = fileAccessI.write (b,0,nRead); r6S-G{o
} XVr>\T4
catch(Exception e){e.printStackTrace ();} QVLv}w`O
} z*n
} Yef=HSzo
(8T36pt~
`Sgj!/!F
//打印回应的头信息 "Zm**h.t
public void logResponseHead(HttpURLConnection con) & mwQj<Z
{ m}ZkNWH
for(int i=1;;i++) E[q:65xl
{ E-gI'qG\(
String header=con.getHeaderFieldKey(i); {w:*t)@j
if(header!=null) U4)x"s[CP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :0@R(ct;>
Utility.log(header+" : "+con.getHeaderField(header)); /e5' YVP
else cq:<,Ke
break; zG-pqE6
} fy9mS
} j3>0oe!
KYa}k0tVAp
Q+@/.qJ
public void splitterStop() [A~n=m5H
{ k{\wjaf)
bStop = true; DwSB(O#X
} DEJ0<pnQr
p[oR4 HWr
<L'!EcHm%]
} 4SRjF$Bsz
eb1WTK@
?.Iau/
/* QA|87alh
**FileAccess.java TQ`s&8"P
*//文件访问(定位，写) UU\wP(f
package NetFox; VWhq+8z
import java.io.*; |Y|6`9;
JTGA\K
zplAH!s5''
public class FileAccessI implements Serializable{ =u\W{1
3oD?e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p+x}$&<|
RandomAccessFile oSavedFile; 6=N!()s
long nPos; RJ}%pA4I
yM,.{m@F<
'`s\_Q)hG_
public FileAccessI() throws IOException ul(pp+%S
{ 7`xeuK
this("",0); Z4ekBdmCL
} (F=/r]Q
A-"2sp*t
VT ikLuH
public FileAccessI(String sName,long nPos) throws IOException ;]gj:6M
{ Dh+<|6mx
oSavedFile = new RandomAccessFile(sName,"rw"); r?9D/|`
this.nPos = nPos; S<*h1}V3/
oSavedFile.seek(nPos); m8}c(GwcP
} J|$UAOEDa
8O^<#lh
g\.O5H9Od
public synchronized int write(byte[] b,int nStart,int nLen) B1^9mV'O
{ r4MPs-}oF
int n = -1; >o/+z18x
try{ B`<a~V
oSavedFile.write(b,nStart,nLen); ]mzghH:E
n = nLen; Mo'6<"x
} M{GT$Q
catch(IOException e) ]g] ]\hS
{ }BYs.$7
e.printStackTrace (); . E8Gj'yO
} DXF>#2E^+
My6a.Kl
.gQYN2#zb
return n; aU\R!Y$/"
} f]sc[_n]
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'@6O3z_{
} S =5br
3g79/w
m=[3"X3W1V
/* "J(T?|t
**SiteInfoBean.java hQb3 8W[
*/ Mq~g+` '
package NetFox; } *:H\GL
tUGnp'r
D[p_uDIz
public class SiteInfoBean { l=&\luNz
ZrNBkfe:
qV{iUtYt
private String sSiteURL; //Site's URL g:oB j6$ q
private String sFilePath; //Saved File's Path b?U2g?lN:
private String sFileName; //Saved File's Name MV.&GUez{
private int nSplitter; //Count of Splited Downloading File Mg~62u
Hb&C;lk
$V870 <
public SiteInfoBean() t) uS7y
{//nSplitter的缺省值为5 d~abWBgC`
//default value of nSplitter is 5 r91b]m3xL
this("","","",5); [gaB}aLn
} j&-<e7O=
)NLjv=ql
P. Kfoos
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Oh=E!
{ b3.}m[]
sSiteURL= sURL; ?Gnx!3Q
sFilePath = sPath; Ud:;kI%Vj
sFileName = sName; ThiM6Hb
this.nSplitter = nSpiltter; U[O7}Nsb"
o_C]O"
(z.4er}o
} eWGaGRem
ET0^_yk
AfT;IG%Gt
public String getSSiteURL() ) :VF^"
{ Y52TC@'
return sSiteURL; { Ba_.]x
} /B!Ik:c}
?s5/
.+A2\F.^
public void setSSiteURL(String value) o?| ]ciY
{ GL-Pir
sSiteURL = value; nN%Zed2O@6
} Pi5($cn
sl_f+h0
TcpaZ 'x
public String getSFilePath() G`r/ tesW
{ ?_`X8Ok
return sFilePath; !NO)|N>
} aZ'(ar:
|hD)=sCj
g[L}puN
public void setSFilePath(String value) P$v9
{ y=&^=Zh[
sFilePath = value; LI9 Uc\
} @(CJT-Ak
E$C0\O!7
m%%\k \
public String getSFileName() VmON}bb[zz
{ MlV3qM@
return sFileName; B=)tq.Q7
} ih=O#f|
3H`r|R
gxc8O).5vY
public void setSFileName(String value) "ph[)/u;
{ )v+\1
sFileName = value; UT%?3}*u"
} .#{m1mr
xM:9XhH1
O ]!/fZ;(
public int getNSplitter() :yFmCLZaQ
{ l.uW>AoLh
return nSplitter; 5ajd$t
} tHmV4H$
"R0(!3
1StaQUB
public void setNSplitter(int nCount) b[^|.>b
{ glomwny
nSplitter = nCount; 2CRgOFR
} 7OD2/{]5
} &?*H`5#?G
i#I7ncX
hQ}y(2A.XI
/* TG6E^3a P
**Utility.java Qe;R3D=T;
*/ .R_-$/ZP
package NetFox; cH`ziZ<&m1
UIo jXR<
)Ec /5=A
public class Utility { E`#/m@:|-
@n;$Edza/
jJ3dZ<#
public Utility() t_hr${
{ ^Is#_Z|
15_Px9
S\0?~l"}
} :+Tvq,/"
Xz!O}M{4
//线程睡眠 \<%?=C'w~
public static void sleep(int nSecond) JgMYy,q8t
{ P;K <P
try{ jg3T1ROL
Thread.sleep(nSecond); IzlmcP3
} g|<$\}
catch(Exception e) -"5r-qq*
{ <xh";seL
e.printStackTrace (); 78kT}kgW
} >dfk2.6e
} #;hYJ Y
V5rW_X:]8
//日志 [&+5E1%L
public static void log(String sMsg) S8Yti
{ =2/[n8pSsM
System.err.println(sMsg); .9!?vz]1
} S?u@3PyJm
cIg+^Tl
qsHjqK@(
public static void log(int sMsg) /{!?e<N>
{ 0[R7HX-@
System.err.println(sMsg); w0,rFWS
} ~ekV*,R"
} eVRjU
Jj7he(!_1
Rz"gPU4;`
/* .Lp\Jyegs
**TestMethod.java Pk^W+M_)~
*/ +&.wc;mi
package NetFox; RP%7M8V){B
THmmf_w@
b$N&sZ
public class TestMethod { c;7`]}fGu
9Bi{X_.9
;mSJZYnT
public TestMethod() L)3JTNiB
{ ///xx/weblogic60b2_win.exe ^ ^k]2oG
try{ %ql2 XAY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d[y(u<Vl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nZ/pi$7
SiteFileFetch fileFetch = new SiteFileFetch(bean); H",q-.!
fileFetch.start(); Mb'Tx
} ;fZ9:WB
catch(Exception e){e.printStackTrace ();} p~17cH4~-f
JQH>{OB
=4804N7
} et}%E9
i7foZ\btFc
2Z7r ZjXW
public static void main(String[] args) ?K= X[
{ 4+q3 Kw
new TestMethod(); =v7%IRP5
} ,L$,d
} &'oZ]}^0
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