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)); c-sjYJXKM*
} Q?#I{l)V(
for(int i=0;i<nEndPos.length-1;i++) 2;8m0+tl
{ `gX@b^
nEndPos = nStartPos[i+1]; 1^!SuAA@
} >Icr4?zq
nEndPos[nEndPos.length-1] = nFileLength; ;V xRaj?
} BmG(+;;&
} QO2cTk m
vrkY7L3\
/ad9Q~nJ
//启动子线程 U ? +_\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x4oWZEd
for(int i=0;i<nStartPos.length;i++) 4J2^zx,H
{ cCe~OlXQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {KG6#/%;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <kak9 6A
nStartPos,nEndPos,i); c.ow4~>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i[o 2(d,
fileSplitterFetch.start(); s6!6Oqh
} !+eH8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vADiW~^Q^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Oynb"T&8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `*C=R _
nEndPos = " + nFileLength); ^[M{s(b
// fileSplitterFetch[nPos.length-1].start(); gc9R;B1
*doNPp)m
bMyld&ga
//等待子线程结束 e$# *t
//int count = 0; FSIiw#xzH
//是否结束while循环 5(3O/C{?~
boolean breakWhile = false; +0'F@l
fw%`[(hK
CSO'``16
while(!bStop) E TT46%Y
{ (W ~K1]
write_nPos(); UB/> Ro
Utility.sleep(500); ZJYn[\]
breakWhile = true; Qp>leEs]+6
Wg']a/m
J ^'El^F
for(int i=0;i<nStartPos.length;i++) Zxa.x?:?n
{ Zh"m;l/]
if(!fileSplitterFetch.bDownOver) [#PE'i4
{ @ZjT_
breakWhile = false; b/wpk~qi
break; |9CikLX)7
} I//=C6
} 6':iW~iI
if(breakWhile) WYP;s7_
break; B5b:znW2@
%6UF%dbYH`
h>-P/
//count++; h051Ol\v*
//if(count>4) I;(3)^QH#
// siteStop(); |#oS7oV(
} /*K2i5&X
!+l'<*8V
=Zd(<&B K
System.err.println("文件下载结束！"); is'V%q
} _BczR:D*
catch(Exception e){e.printStackTrace ();} al2t\Iq90
} MdHm%Vx
8-q^.<9
Harg<l
//获得文件长度 }E'0vf/
public long getFileSize() t]/eCsR
{ Nk|cU;?+
int nFileLength = -1; j(;^XO Y#
try{ O$Rz/&
URL url = new URL(siteInfoBean.getSSiteURL()); p"g|]@m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,eXtY}E
httpConnection.setRequestProperty("User-Agent","NetFox"); h>N}M}8
7=!9kk0
wPA^nZ^}9c
int responseCode=httpConnection.getResponseCode(); $l7^-SK`E
if(responseCode>=400) 64s;EC
{ $[gN#QW%
processErrorCode(responseCode); 8bIP"!=*W
return -2; //-2 represent access is error ]lB zpD
} 5xQ-f
>=~\b
$ghZ<Y2}9
String sHeader; }3pM,.
@<.@X*#I
NYm"I`5w
for(int i=1;;i++) vQAFgG
{ 5KCB^`|b>t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nxLuzf4U5
//Utility.log(in.readLine()); !X>u.}?g
sHeader=httpConnection.getHeaderFieldKey(i); e+ xQ\LH
if(sHeader!=null) Sj9fq*
{ YOCEEh?
if(sHeader.equals("Content-Length")) $.G 7Vt
{ 9U8M|W|d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S,Y|;p<+^
break; c}(WniR-"
} %)ho<z:7U
} K,b M9>}
else 0-. d{P
break; r*X,]\V0x
} `Q]N]mK
} &Y@i:O
catch(IOException e){e.printStackTrace ();} |3H+b,M5
catch(Exception e){e.printStackTrace ();} )2}R1K>
\2SbW7"/;P
N8<J'7%
Utility.log(nFileLength); )^2eC<t
qd`e:s*%
>ohH4:
return nFileLength; &w@]\7L,:
} DaQ"Df_X
n 8cA8<
v2T2/y%
//保存下载信息（文件指针位置） 0I}e>]:I
private void write_nPos() 'B@`gA
{ 0[;2dc
try{ X>q`F;W
output = new DataOutputStream(new FileOutputStream(tmpFile)); lu8G$EQI
output.writeInt(nStartPos.length); ]hl*6
for(int i=0;i<nStartPos.length;i++) 12$0-@U
{ 7[m?\/K~
// output.writeLong(nPos); ."Ms7=
output.writeLong(fileSplitterFetch.nStartPos); 1{}p_"s>
output.writeLong(fileSplitterFetch.nEndPos); JA^o/%a^
} ^X#y'odtbS
output.close(); RObnu*
} +v~xgUs
catch(IOException e){e.printStackTrace ();} i"{O~[
catch(Exception e){e.printStackTrace ();} T$Z9F^w
} TpjiKM
y^.66BH
*}[\%u$ T
//读取保存的下载信息（文件指针位置） ;>6< u.N
private void read_nPos() RLF&-[mr3
{ GES}o9?#
try{ qJey&_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }@DCcf$<
int nCount = input.readInt(); )SV.|
nStartPos = new long[nCount]; MKK ^-T
nEndPos = new long[nCount]; g \mE
for(int i=0;i<nStartPos.length;i++) N0`9/lr|
{ !_W:%t)g
nStartPos = input.readLong(); blO4)7m
nEndPos = input.readLong(); 2q f|+[X
} #-{<d%qk
input.close(); U,P_bz*)
} k.J%rRneN
catch(IOException e){e.printStackTrace ();} ofvR0yV
catch(Exception e){e.printStackTrace ();} UwN Vvo
} `L1,JE` q
C]^Ep
i'~-\F!
private void processErrorCode(int nErrorCode) k"wQ9=HP7
{ :]3X Ez
System.err.println("Error Code : " + nErrorCode); Vl^(K_`(
} !_I1=yi
spK8^sh
I-#H+\S
//停止文件下载 F(")ga$r
public void siteStop() &@=Jm /5
{ }=R]<`Sj.j
bStop = true; QM$UxWo-
for(int i=0;i<nStartPos.length;i++) ZOK!SBn^?
fileSplitterFetch.splitterStop(); 5_yQI D%Sq
6[bopin
D9rQ%|}S
} *TOdIq&z
} .i0K-B
//负责部分文件的抓取 8%rD/b6`
**FileSplitterFetch.java &L|oqXE0L
*/ q'3{M]Tk
package NetFox; mz?<t/$U
So%X(, |
jNZ.Fb
import java.io.*; )u?f| D
import java.net.*; 4pmeu:26
=lacfPS
U,GSWMI/K
public class FileSplitterFetch extends Thread { zzmC[,u}
_,3ljf?WQM
bG;fwgAr
String sURL; //File URL Vaxg
long nStartPos; //File Snippet Start Position !-I,Dh-A
long nEndPos; //File Snippet End Position 4.A^5J'W
int nThreadID; //Thread's ID q^X7x_
boolean bDownOver = false; //Downing is over w,|@e_|J
boolean bStop = false; //Stop identical unDW2#GX
FileAccessI fileAccessI = null; //File Access interface 3:nhZN/95T
0KA*6]h t
mF~T?L"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %h.zkocM
{ U~G7~L &m
this.sURL = sURL; *,u3Wm|7
this.nStartPos = nStart; 2=cx`"a$
this.nEndPos = nEnd; +LHU}'|
nThreadID = id; *CN *G"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LKN7Lkl
} @2(u=E:^
)"x6V""Rb
"M%R{pGA7
public void run() 8t+eu O
{ ]4~Yi1]
while(nStartPos < nEndPos && !bStop) +IZ=E >a
{ VZ]iep
UB~K/r`.|
e02Hf{eOfw
try{ .ARYCTyG
URL url = new URL(sURL); F`=p/IAJK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0d2P
httpConnection.setRequestProperty("User-Agent","NetFox"); S!K<kn`E3
String sProperty = "bytes="+nStartPos+"-"; U1\EwBK8*T
httpConnection.setRequestProperty("RANGE",sProperty); 3Tr,waV
Utility.log(sProperty); dJuyJl$*
fe .=Z&
c!w[)>v
InputStream input = httpConnection.getInputStream(); }G4I9Py
//logResponseHead(httpConnection); "&L8d(ZuA
,%!m%+K9a
VH7t^fb
byte[] b = new byte[1024]; N2:Hdu:
int nRead; XJul~"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T!/o^0w
{ xd?=#d
nStartPos += fileAccessI.write(b,0,nRead); NKY|Z\
//if(nThreadID == 1) i0M6;W1T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B>{%$@4
} (l5p_x
^^q&VL
%:26v
Utility.log("Thread " + nThreadID + " is over!"); d+n2 c`i
bDownOver = true; {lK2yi
//nPos = fileAccessI.write (b,0,nRead); <ZT C^=3
} eP~bl
catch(Exception e){e.printStackTrace ();} wd:Yy
} 9qX$
} YS3~sA
2EgvS!"
@@R Mm$
//打印回应的头信息 ]*dYX=6
public void logResponseHead(HttpURLConnection con) s|IBX0^@
{ OvH:3"Sdy
for(int i=1;;i++) sRB=<E*_
{ |v+z*}fKw
String header=con.getHeaderFieldKey(i); 9J:|"@)N
if(header!=null) l|q-kRRjn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9nY`rF8@
Utility.log(header+" : "+con.getHeaderField(header)); \? /'
else Whd >
break; @9^OHRZX
} w4fKh
} j"Jf|Hq $
|E~c#lV
bQD8#Ml1
public void splitterStop() =r]l"T
{ Xg~9<BGsi
bStop = true; ?HG[N7=j
} Wvl~|Sx]
Q{~g<G
y&(#C:N
} y;o - @]
<F^9ML+'
$9%F1:u
/* Y:CX RU6eD
**FileAccess.java i]n2\v AG
*//文件访问(定位，写) /? %V% n
package NetFox; I`{3I-E
import java.io.*; xLed];2G
%P}H3;2
= #-zK:4
public class FileAccessI implements Serializable{ ;*?>w|t}w
SM~~:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gk%01&_>4
RandomAccessFile oSavedFile; ,h=a+ja8
long nPos; ,^bgk -x-
:2lpl%/
<M9NyD`
public FileAccessI() throws IOException ?22U0UF
{ s AFn.W
this("",0); &~2m@X(o
} 3JC uM_y
1 b7jNkQ
b |:Y3_>
public FileAccessI(String sName,long nPos) throws IOException "{8j!+]4i
{ JuZkE9C,${
oSavedFile = new RandomAccessFile(sName,"rw"); 7V%P
this.nPos = nPos; -sJ1q^;f@
oSavedFile.seek(nPos); 1v&!%9
} 9(t(sP_
;6@sC[
HGAi2+&
public synchronized int write(byte[] b,int nStart,int nLen) s(py7{ ^K
{ gaN/ kp
int n = -1; uD/@d'd_4L
try{ z5gVP8*z5
oSavedFile.write(b,nStart,nLen); UvGxA[~2+
n = nLen; 9mxg$P4
} ]Y?Y$>
catch(IOException e) Z*M{
{ Jqb~RP~
e.printStackTrace (); ,>aa2
} D?#l8
A6[FH\f
3IRur,|'
return n; OxDqLX
} e6MBy\*n
=?$~=1SL+
N!ihj:,
} LEM%B??&5z
a4UwhbH
='jT 5Mg
/* j^=Eu r/
**SiteInfoBean.java NWh1u`
*/ frUs'j/bZ
package NetFox; c\n_[r
LxIGPC~
3w)r""C&
public class SiteInfoBean { _<RTes
PR5N:Bw
|Uics:cQC
private String sSiteURL; //Site's URL {C&Uq#V
private String sFilePath; //Saved File's Path 1UK= t
private String sFileName; //Saved File's Name "dP-e
private int nSplitter; //Count of Splited Downloading File ,c:NdY(,)
EMP|I^
)Xqjl
public SiteInfoBean() g*a+$'
{//nSplitter的缺省值为5 6yy%_+k*
//default value of nSplitter is 5 .v(GVkE}
this("","","",5); wH8J?j"5>
} ,=\.L_'
MrzD ah9UG
T^Ia^B-%}g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )Zr\W3yWX
{ .8W-,R4
sSiteURL= sURL; m"rht:v5
sFilePath = sPath; N ;=zo-8
sFileName = sName; Y_Fn)(
this.nSplitter = nSpiltter; 6 eryf?
PwW$=M{\.
"LTw;& y
} A:ts_*
=s!0EwDH3
Mv%Qze,\V^
public String getSSiteURL() zc8^#D2y&
{ vYm-$KQ"o
return sSiteURL; ~qQZhu"
} L9O;K$[s
@Dfg6<0
)YgntI@
public void setSSiteURL(String value) F oC $X
{ |;NfH|43;
sSiteURL = value; WYb}SI(E
} }Q4Vy
?|kbIZP(
@*|VWHR
public String getSFilePath() g;=VuQuP|
{ xI{fd1
return sFilePath; t3<8n;'y:
} 27N;>
)qb'tZz/g_
OW#0$%f
public void setSFilePath(String value) 6&0@k^7~
{ %d];h
sFilePath = value; <[\I`kzq
} +# 'w} P
d)1gpRp
AE>W$x8P
public String getSFileName() VIdKe&,
{ msgR"T3'
return sFileName; o3hgkoF
} ;Tr,BfV|Bf
F}{%*EJ
QP.Lq}
public void setSFileName(String value) -9FGFBm4]
{ ld]*J}cw
sFileName = value; 1s(T#jh
} g ptf*^s
xjr4')h
:+DrV\)
public int getNSplitter() SI~jM:S}
{ jbipNgxkr
return nSplitter; vN^.MR+<
} V3ht:>c9qs
~D3S01ecM
s>o#Ob@4'
public void setNSplitter(int nCount) *gH]R*Q[Rt
{ b]b>i]n
nSplitter = nCount; BL 1KM2]
} '>t&fzD0
} iH4LZ
uCr& `
BJwuN
/* _M/N_Fm
**Utility.java #?w07/~L
*/ .2c/V
package NetFox; I+H~ 5zq.
%4m Nk}tyH
g8uqW1E^
public class Utility { dvjj"F'Bf
UgAp9$=z
'27$x&6>S
public Utility() xx!8cvD4?
{ OUUV8K
"jyo'r
D<69xT,
} 6}-No
W"Y)a|rG%
//线程睡眠 Ur#jJR@%3
public static void sleep(int nSecond) +Mq\3
{ QO}~"lMj
try{ SM8N*WdiU
Thread.sleep(nSecond); ':pDlUA
} ns>$
catch(Exception e) E#+2)Q
{ RJ@79L*#
e.printStackTrace (); Xd%qebK
} :W0p36"
} *|Vf1R]
:ZY%-]u7
//日志 3eE=>E4,
public static void log(String sMsg) DWOf\[
{ 3S3(Gl
System.err.println(sMsg); +"-l~`+<es
} u!|_bI3
,Suk_aX>
Axsezr/
public static void log(int sMsg) jKmjZz8L]%
{ D/Ki^E
System.err.println(sMsg); /al56n
} FTCIfW
} <VhmtT%7
THhxj)
_y[C52,
/* fE~KWLm
**TestMethod.java se %#U40*
*/ e-y$&[
package NetFox; `.J)Z=o
B1_9l3RM
gZtQtFi
public class TestMethod { Ob]\t/:%P
b5)^g+8)w
"b`#RohCi
public TestMethod() dh`s^D6Q>
{ ///xx/weblogic60b2_win.exe [T_[QU:A
try{ e#Ao]gc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6d]4 %QT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a%Q`R;W
SiteFileFetch fileFetch = new SiteFileFetch(bean); c qCNk
fileFetch.start(); ):PN0.H8
} xF!IT"5D
catch(Exception e){e.printStackTrace ();} 6"G(Iq'2t3
"L]v:lg3
]Ik~TW&
} }&=l)\e
OU%"dmSDk
P_3IFHe
public static void main(String[] args) VYb,Hmm>kC
{ Ld*Ds!*'/
new TestMethod(); #a=]h}&1?
} 4j3_OUwWZx
} ivgX o'=
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