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)); F$s:\N
} ]P_yN:~
for(int i=0;i<nEndPos.length-1;i++) =Q# (2
{ n"I{aJ]K
nEndPos = nStartPos[i+1]; r0<zy_d'
} /BS yanro
nEndPos[nEndPos.length-1] = nFileLength; a0k/R<4
} dA#'HMh@
} z wn#E
)ItW}1[I
!Ks<%; rb
//启动子线程 4`sW_ ks
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U]M5&R=?
for(int i=0;i<nStartPos.length;i++) UD&pL'{s
{ usU6,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;|,*zD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K7,Sr1O `
nStartPos,nEndPos,i); _Q*,~ z~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EO/TuKt
fileSplitterFetch.start(); {P==6/<2o
} [KEw5-=i@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &<(&u`S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0<Rq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =>e> r~cW
nEndPos = " + nFileLength); =)!~t/
// fileSplitterFetch[nPos.length-1].start(); m&--$sr
A4)TJY 3g
dFk$rr>q
//等待子线程结束 ^HWa owy=
//int count = 0; nKch:g
//是否结束while循环 Upc_"mkI.
boolean breakWhile = false; Xz'o<S
QOv@rP/
iG{xDj{CKv
while(!bStop) M?qvI
{ nYTPcT4x|
write_nPos(); ,UxAHCR~9
Utility.sleep(500); !dwa. lZ&X
breakWhile = true; u"U7aYGkY
mfk^t`w_
pvdCiYo1r
for(int i=0;i<nStartPos.length;i++) 'On%p|s)H
{ XrGP]k6.^
if(!fileSplitterFetch.bDownOver) I$ ?.9&.&
{ &Y2Dft_K
breakWhile = false; tf>"fU\P
break; -=2V4WU~
} TV?MB(mN
} ]9}^}U1."
if(breakWhile) qy/t<2'
break; 1-sG`%
;IR.6k$;
G54`{V4&s
//count++; /PEL[Os
//if(count>4) Oh,]"(+
// siteStop(); Cq}E5M
} q!YAA\'31
z6 .^a-sU5
`ix&j8E22w
System.err.println("文件下载结束！"); /1b7f'
} `r&]Ydu:
catch(Exception e){e.printStackTrace ();} h*\u0yD)
} pL2{zW`FDh
&W*^&0AV
M[QQi2:&
//获得文件长度 c-ql
public long getFileSize() |u+!CR
{ /z: mi
int nFileLength = -1; dQy K4T
try{ ipS:)4QFxJ
URL url = new URL(siteInfoBean.getSSiteURL()); V+t's*9o3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m"wP]OQH*+
httpConnection.setRequestProperty("User-Agent","NetFox"); N t\ZM
Yw_!40`
xL"O~jTS
int responseCode=httpConnection.getResponseCode(); o_03Io ~Bf
if(responseCode>=400) Y} 6@ w
{ S1U[{R?,
processErrorCode(responseCode); BO.Db``
return -2; //-2 represent access is error \}_,g
} ~7m+N)5
e9>~mtx
z, n[}Q#u
String sHeader; gj I>tz}
=Q*3\)7
45WJb+$
for(int i=1;;i++) L+}<gQJ(
{ P~%+KxwZQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b7B|$T,
//Utility.log(in.readLine()); UqNUX?(
sHeader=httpConnection.getHeaderFieldKey(i); U>DCra;
if(sHeader!=null) kT:I.,N
{ tHK>w%|\R
if(sHeader.equals("Content-Length")) zjOOEvi
{ B<0Kl.V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h`iOs>
break; mhB2l/
} -+0kay%
} wxYGr`f
else opMnLor
break; `evF?t11X
} 5lM2nhlf'b
} 'u~0rMe4})
catch(IOException e){e.printStackTrace ();} W#=,FZT
catch(Exception e){e.printStackTrace ();} hCS}
y G3aF(
]Y!x7
Utility.log(nFileLength); ESYF4-d+
<'N:K@Cs
Q<gUu^rq
return nFileLength; 2t PfIg
} e.~11bx
gY8$Rk %
P-3f51Q
//保存下载信息（文件指针位置） Eku9u
private void write_nPos() G? XS-oSv
{ -$DfnAh
try{ Ri~$hs!
output = new DataOutputStream(new FileOutputStream(tmpFile)); B(ktIy
output.writeInt(nStartPos.length); *UJ4\
for(int i=0;i<nStartPos.length;i++) gKQV99
{ 6su~SPh
// output.writeLong(nPos); /;Hr{f jl{
output.writeLong(fileSplitterFetch.nStartPos); {/H<_
output.writeLong(fileSplitterFetch.nEndPos); O1S7t)ag
} >7zC-3
output.close(); ^ nI2<P
} F"UI=7:o
catch(IOException e){e.printStackTrace ();} JO+tY[q
catch(Exception e){e.printStackTrace ();} x7U=1y(
} 8-B7_GoJ+B
YWvD+
{:|3V 7X
//读取保存的下载信息（文件指针位置） ir/uHN@
private void read_nPos() N+@ Ff3M
{ yCvtglAJ4
try{ cw{TS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `Y5LAt:
int nCount = input.readInt(); KE@+I.x
nStartPos = new long[nCount]; { ]_j)R
nEndPos = new long[nCount]; eqsmv[
for(int i=0;i<nStartPos.length;i++) 7XK0vKmW3
{ 66,(yxg
nStartPos = input.readLong(); nqm=snh
nEndPos = input.readLong(); 4P k%+l
} 2Y23!hw
input.close(); bo/9k 4N3
} HyVV,q^E
catch(IOException e){e.printStackTrace ();} <Q\KS
catch(Exception e){e.printStackTrace ();} %DYh<U4N
} +tT"
T+ZA"i+
,MNv}w@
private void processErrorCode(int nErrorCode) wW1VOj=6V"
{ n@RmH>"
System.err.println("Error Code : " + nErrorCode); ={sjoMW
} CTRUr"
c 'wRGMP
iX]OF.:
//停止文件下载 EXCE^Vw
public void siteStop() $|-Lw!)D
{ mi7?t/D1Z
bStop = true; *VsVCUCz5*
for(int i=0;i<nStartPos.length;i++) kt2_WW[
fileSplitterFetch.splitterStop(); fq6Obh=A#
9 A ?{}c
'7sf)0\:<p
} S F*C'
} S3ooG14Ls
//负责部分文件的抓取 Op ar+|p\
**FileSplitterFetch.java cZNcplt8
*/ E=ijt3
package NetFox; $lJcC |*
!Ud'(iGa
["EXSptB
import java.io.*; !HDb{f
import java.net.*; 0w3c8s.
E{u6<B*
FpRYffT 9u
public class FileSplitterFetch extends Thread { f[k#Znr
CW &z?Bra
\dtiv&x
String sURL; //File URL 1n8[fgz
long nStartPos; //File Snippet Start Position H~+A6g]T
long nEndPos; //File Snippet End Position 2F:qaz
int nThreadID; //Thread's ID \9VF)Y.ke
boolean bDownOver = false; //Downing is over .C% 28fH
boolean bStop = false; //Stop identical Z v@nK%#J
FileAccessI fileAccessI = null; //File Access interface {=ox1+d
$9,&BW_*
,/{e%J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QM0B6F
{ '[{<aEo
this.sURL = sURL; Jp=fLo 9
this.nStartPos = nStart; <=*f
this.nEndPos = nEnd; ':vZ&
nThreadID = id; c C3>Ff'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %qoS(iO`h
} )!"fUz$
=8\.fp
j<p.#jkT
public void run() :-1|dE)U
{ ? }M81
while(nStartPos < nEndPos && !bStop) [s(D==8
{ @j/2 $
nq M7Is
Za:j;u Y
try{ U] LDi8
URL url = new URL(sURL); Xqf,_I=V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ``-N2U5
httpConnection.setRequestProperty("User-Agent","NetFox"); 5RP kAC
String sProperty = "bytes="+nStartPos+"-"; /|0-O''
httpConnection.setRequestProperty("RANGE",sProperty); [;u#79aE
Utility.log(sProperty); q)k:pQ
N6Mr#A-{
X94a
InputStream input = httpConnection.getInputStream(); UY',n,
//logResponseHead(httpConnection); f<YYo
|b
Og\k5.! ,
byte[] b = new byte[1024]; ~non_pJ
int nRead; M-o'`e'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 23}` e
{ n>Ff tVZNJ
nStartPos += fileAccessI.write(b,0,nRead); s<O$ Y
//if(nThreadID == 1) ~aob@(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8SGaS&
} 9wvlR6z;u
QQ(}71U
L+am-k:T~
Utility.log("Thread " + nThreadID + " is over!"); 3Ua?^2l
bDownOver = true; EW `hL~{
//nPos = fileAccessI.write (b,0,nRead); 6Tl6A>%s
} GKBoSSnV&
catch(Exception e){e.printStackTrace ();} A8)4nOXM
} XiW1X6
} Yuvi{ 0
]5ZXgz
,d#*i
//打印回应的头信息 8u[_t.y4m
public void logResponseHead(HttpURLConnection con) WK{`_c U^
{ 51|ky-
for(int i=1;;i++) @>2pY_
{ +9_Y0<C
String header=con.getHeaderFieldKey(i); da$FY7
if(header!=null) y9:4n1fg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Tgdy;?
Utility.log(header+" : "+con.getHeaderField(header)); d][ Wm
else oZ'a}kF
break; N^L@MR-
} 8x{Owj:Q
} x?h/e;
9K+>;`
2\xw2VQ@P
public void splitterStop() ~7]V^tG
{ *8}b&4O~
bStop = true; 9zp!lw~;+
} &,nv+>D
1QoW/X'>.
\[MAa:/
} I ]m
y'R}
RTOA'|[0M
/* fLDrit4_Q
**FileAccess.java !_Lmrs
*//文件访问(定位，写) Sc<dxY@w7-
package NetFox; }icCp)b>v
import java.io.*; '/d51
pj>R9zpn_
+}:Z9AAMy
public class FileAccessI implements Serializable{ j}+3+ 8D
vm [lMx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `^M]|7
RandomAccessFile oSavedFile; IskL$Y ^
long nPos; \]X.f&u
l]*RiK2AC
7)Toj
public FileAccessI() throws IOException )qWwh)\;!
{ pKSCC"i&j
this("",0); u?^V4 +V
} oRV}Nz7hr
iN;Pg_Kq
xGd60"w2
public FileAccessI(String sName,long nPos) throws IOException RT[p!xL
{ cx\"r
oSavedFile = new RandomAccessFile(sName,"rw"); .;? Bni
this.nPos = nPos; ]J7qsMw
oSavedFile.seek(nPos); =KE7NXu]-
} SuE~Wb5&
"zEl2Xn28_
4Gu'WbJ
public synchronized int write(byte[] b,int nStart,int nLen) g4?2'G5m?
{ Oa[
int n = -1; %|-N{>wKy
try{ |XyX%5p*
oSavedFile.write(b,nStart,nLen); 74%vNKzc~
n = nLen; ~1G^IZ6
} ptCF))Zm'
catch(IOException e) \:vF FK4a
{ I68u%fCv
e.printStackTrace (); Y{Z&W9U
} 8v$q+Wic
E0Wc8m"
T7[@ lMa?
return n; vq$6e*A
} `PWKA;W$0
yV^Yp=f_
4]d^L>
} IwyA4Ak Ru
OSu&vFKz
>M<3!?fW)
/* @6 he!wW
**SiteInfoBean.java DB vM.'b$
*/ Q):#6|u+
package NetFox; +=tdgw/
Wf~^,]9N
w-|Rb~XT h
public class SiteInfoBean { @|gG3
UHl3/m7g
!0{SVsc)
private String sSiteURL; //Site's URL ]kj^T?&n.
private String sFilePath; //Saved File's Path Jqoo&T")
private String sFileName; //Saved File's Name Yh<F-WOo2
private int nSplitter; //Count of Splited Downloading File )nm+_U
4n,&,R r#
V)$!WPL@
public SiteInfoBean() C5~#lNC
{//nSplitter的缺省值为5 t{k:H4
//default value of nSplitter is 5 !I7$e&Uz@
this("","","",5); Aztrq
} Xaz "!
=*UK!y?n
!BQt+4G7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $QJ3~mG2
{ *i"9D:
sSiteURL= sURL; xm m,-u
sFilePath = sPath; o/AG9|()4
sFileName = sName; ~j!n`#.\
this.nSplitter = nSpiltter; i"Jy>'
(4H\ho8+mp
T?3Q<[SmI
} h.<f%&)F
d`sZ"8}j
vC]X>P5Px
public String getSSiteURL() *byUqY3(
{ x^s,<G
return sSiteURL; f;E#CjlTL
} +d, ~h_7!
ieyK$q
^t0!Dbx3SE
public void setSSiteURL(String value) .6y+van
{ M;A_'h?Z
sSiteURL = value; [RF,0>^b
} K^WDA])
%.bDK}
1_Yx]%g<
public String getSFilePath() C4m+Ta%
{ QqM[W/&R
return sFilePath; P(T-2Ux6
} Ca-"3aQkc
f2gtz{r
f3UCELJ
public void setSFilePath(String value) KhjC'CU,
{ `Vvi]>,cg`
sFilePath = value; ^G4YvS(
} TQR5V\{&%
CJ<nUIy'z
y|LHnNQ
public String getSFileName() /^=1]+_!
{ :Xw|v2z%3
return sFileName; -2.7Z`*(
} +wi=IrRr
zTng]Mvx
n|5\Q
public void setSFileName(String value) Y3 $jNuV
{ fU6YJs.H^8
sFileName = value; x`6MAZ
} s&73g0$$
(~~m8VJ>
w:\} B'u
public int getNSplitter() !5,C"r
{ ~RR!~q
return nSplitter; (T1< (YZ
} &2ED<%hH`
Jv}
{!Qu(%
public void setNSplitter(int nCount) ^4sfVpD2!
{ fD!c t;UK
nSplitter = nCount; G)vNMl
} Nj9A-*0g6N
} FC0fe_U(F
_c-3eQ1
V.Hv6
/* N,Y)'s<
**Utility.java Zc7;&cz
*/ w$ 8r<?^3
package NetFox; P@N+jS`Vf
/
<+QdBp'd;
public class Utility { GDLw_usV
xvl$,\iqE
v,")XPY
public Utility() 8maWF.xq
{ x/,;:S
12 p`ZD=
\HGf!zZ
} R+LKa Z
1Vpti4OmU
//线程睡眠 rC8p!e.yL
public static void sleep(int nSecond) #-yCR
{ Lx,=Up.
try{ >)M{^
Thread.sleep(nSecond); ]p!{
} xXJ*xYn"}
catch(Exception e) xsa`R^5/c
{ FWbp;v{
e.printStackTrace (); _LJF:E5L
} /A{ Zf'DI
} K P]ar.
hYoUZ'4
//日志 jOGdq;|
public static void log(String sMsg) kmC@\xTp
{ B4.: 9Od3
System.err.println(sMsg); %bnXZA2Sx
} svpQ.Q
H<d~AurX)J
7d;|?R-8D
public static void log(int sMsg) HzTmNm)
{ ,AnD%#o
System.err.println(sMsg); 6b|<$Je9
} R`(2Fy%0\k
} 9KVJk</:n
]BO:*&O
>.meecE?Q
/* wn"}<ka
**TestMethod.java c}(H*VY2n
*/ Z- feMM
package NetFox; C8m9H8Qm
b,'O|s]"Sc
01A{\O1$j
public class TestMethod { ` -_!%m/
8w5}9}xF
X%yG{\6:
public TestMethod() x;~:p;]J2F
{ ///xx/weblogic60b2_win.exe UWT%0t_T
try{ o]1BWwtY&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a7g;8t-&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9@|52dz%
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5%jhVys23
fileFetch.start(); <YyE1|
} (%6fMVp
catch(Exception e){e.printStackTrace ();} |nNcV~%~
Sf?;j{?G
Vuz.b.,i`
} R*r4)+gd
v~mVf.j1
?+]=|hN
public static void main(String[] args) ZDW9H6ux
{ i<Z%
new TestMethod(); B|m)V9A%-
} &J3QO%
} 3RaduN]
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