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)); 8|nc($}~
} +R7pdi
for(int i=0;i<nEndPos.length-1;i++) BSL+Gjj~}
{ Fkg%_v$
nEndPos = nStartPos[i+1]; B.!&z-)#
} c D.;
nEndPos[nEndPos.length-1] = nFileLength; jZH4]^De
} uqD|j:~ =k
} 1SH]$V4C
Yr\quinLL
,4=mlte"
//启动子线程 $wyPGok
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QX42^]({;c
for(int i=0;i<nStartPos.length;i++) 2.^CIJc
{ "YAnGGx)LZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >*uj )u%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q8uq%wf
nStartPos,nEndPos,i); O`I}Lg]~q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~~O4!|t
fileSplitterFetch.start(); ,fhF-%Q!g
} `(DHa=s1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "$P/ek
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I%($,kd}s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U5OFw+J
nEndPos = " + nFileLength); pWn]$HaoG
// fileSplitterFetch[nPos.length-1].start(); M& )yr^
Vvp{y
I2-ue 63 ?
//等待子线程结束 KEdqA/F>
//int count = 0; \6bvk_
//是否结束while循环 +_25E.>ml
boolean breakWhile = false; ~YenH
=nO:R,U
]+b?J0|P<
while(!bStop) WJI}~/z;C
{ .Yvy37n((
write_nPos(); lANi$ :aE
Utility.sleep(500); ,tDLpnB@;
breakWhile = true; J@QOF+&
DliDBArxZ
aHb&+/HZ
for(int i=0;i<nStartPos.length;i++) #s' `bF^
{ F+?i{$
if(!fileSplitterFetch.bDownOver) XfflD9M
{ &g>MZ"Z|
breakWhile = false; cP4C<UG
break; m2/S(f
} Udf\;G@
} B.KK@
if(breakWhile) CEBu[TT/9
break; O9m sPb:
zo("v*d*q
#DARZhU)
//count++; m%UF{I,
//if(count>4) '+ mI
// siteStop(); atW^^4:
} t~)4f.F:
df {\O*6
Ujqnl>l
System.err.println("文件下载结束！"); @' %XdH
} i[MBO`FF
catch(Exception e){e.printStackTrace ();} K9Onjs%U
} SL/'UoYm<
.Wr7*J[V.
v;-0^s/P
//获得文件长度 >5?c93?
public long getFileSize() kw} E0uY
{ j+S&5C/{
int nFileLength = -1; -ik=P]?
try{ j}K3YfH
URL url = new URL(siteInfoBean.getSSiteURL()); Zop/ MeI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4^k8|#c
httpConnection.setRequestProperty("User-Agent","NetFox"); [z"oi'"fQ
)2q r^)
!I\eIV>0b
int responseCode=httpConnection.getResponseCode(); P: L6Zo-J
if(responseCode>=400) K>5bb
{ LN5BU,4=
processErrorCode(responseCode); F_i"v5#
return -2; //-2 represent access is error #f;6Ia>#
} _|4QrZ$n(
.r&CIL>
1f1D^|
String sHeader; IwS<p-
|'uBkL0q
ueg%D+u
for(int i=1;;i++) Q[%G`;e#
{ J_j4Zb% K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >e(@!\ x
//Utility.log(in.readLine()); MxUQF?@6
sHeader=httpConnection.getHeaderFieldKey(i); /?0|hi<_$
if(sHeader!=null) Wb#<ctM>
{ L>&{<M_
if(sHeader.equals("Content-Length")) WvoIh4]
{ 9$qw&j[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -e?n4YO*\
break; VKw.g@BY
} XR p60i6f
} lqgR4 !
else osmCwM4O
break; Jt0/*^'
} 5\O&pz@D
} XbeT x
catch(IOException e){e.printStackTrace ();} 2P${5WT
catch(Exception e){e.printStackTrace ();} :cIPX%S
*b!.9pK
k_Sm ep
Utility.log(nFileLength); K6)IBV;
!>wu7u-
f_;tFP B
return nFileLength; t$p%UyVE
} PI9aKNt
Uqx@9z(
bE=[P}E
//保存下载信息（文件指针位置） V\Y,4&bI
private void write_nPos() JlawkA
{ h/y0Q~|/d
try{ #N'9F&:V$
output = new DataOutputStream(new FileOutputStream(tmpFile)); u[4h|*'"|
output.writeInt(nStartPos.length); @at*E%T[
for(int i=0;i<nStartPos.length;i++) |5q,%9_
{ iCGHcN^3
// output.writeLong(nPos); .b!HEi<F
output.writeLong(fileSplitterFetch.nStartPos); V`i(vC(
output.writeLong(fileSplitterFetch.nEndPos); E0aFHC[
} BLt_(S?Z`
output.close(); Se\iMs
} e5lJ)_o
catch(IOException e){e.printStackTrace ();} aW;)-0+
catch(Exception e){e.printStackTrace ();} 1Mx2%
} U+(qfa5(
C.H(aX)7
V' i@N
//读取保存的下载信息（文件指针位置） uKJo5%>
private void read_nPos() lQt,(@7]
{ B{S^t\T$
try{ mZ3Z8q}%P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wh"xt:
int nCount = input.readInt(); :;LaV
nStartPos = new long[nCount]; Y[m*
nEndPos = new long[nCount]; D$D;'Kij
for(int i=0;i<nStartPos.length;i++) D.a\O9q"&{
{ s%m?Yh3
nStartPos = input.readLong(); c"Q9ob
nEndPos = input.readLong(); o?3C-A|
} BHNJH
input.close(); qA25P<
} U9%^gC
catch(IOException e){e.printStackTrace ();} 'g}Q@@b
catch(Exception e){e.printStackTrace ();} >{rD3X"d
} ?8<R)hJa<
<BBSC
fq):'E)
private void processErrorCode(int nErrorCode) M{Vi4ehOq
{ jq|fIP
System.err.println("Error Code : " + nErrorCode); ]*{tno
} jT-tsQ .,
Go~3L8 '
:/fT8KCwo
//停止文件下载 :D !/.0
public void siteStop() F7=&CW 0
{ k4"O}jQO
bStop = true; _gCi@uXS3
for(int i=0;i<nStartPos.length;i++) Rp}Sm,w(
fileSplitterFetch.splitterStop(); Q[aBxy (
H^$7=
5<oV>|*@{
} Ik=bgEF
} ag!q:6&
//负责部分文件的抓取 A{DE7gp!
**FileSplitterFetch.java Z[\nyj
*/ ),-MrL8c%
package NetFox; _M- PF$
WOYN% 0#
i[vOpg]J
import java.io.*; H1vToIP%
import java.net.*; th{Ib@o
r#6djs1
#!4 HSBf
public class FileSplitterFetch extends Thread { I5rAL\y-G
-8t&&fIA
n3s
String sURL; //File URL U{9yfy
long nStartPos; //File Snippet Start Position IBh?vh
long nEndPos; //File Snippet End Position )hfI,9I~
int nThreadID; //Thread's ID uC 2{ Mmy
boolean bDownOver = false; //Downing is over 0qN+W&H
boolean bStop = false; //Stop identical o&?:pE
FileAccessI fileAccessI = null; //File Access interface l<s6Uu"
A_5M\iN\
]Lm?3$u$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^F|/\i
{ difAQ<`
this.sURL = sURL; {9nH#yv
this.nStartPos = nStart; v%E!
this.nEndPos = nEnd; 4Jw_gOY&D
nThreadID = id; @ |(Tg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MQo/R,F }
} (<Kf
q]P$NeEiZ"
}>'1Qg
public void run() E*}1_,q)
{ l9{.~]V
while(nStartPos < nEndPos && !bStop) |vh{Kb@
{ ;n/04z
Ve[&_(fP
6>Is-/hsy
try{ }FC(Z-g
URL url = new URL(sURL); M#SGZ~=1r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :g)`V4%
httpConnection.setRequestProperty("User-Agent","NetFox"); _%PEv{H0.
String sProperty = "bytes="+nStartPos+"-"; 7qhX`$
httpConnection.setRequestProperty("RANGE",sProperty); l3YS_WBSn
Utility.log(sProperty); [4\n(/
zj#8@gbh+
c7 O$< F
InputStream input = httpConnection.getInputStream(); 5 r&n
//logResponseHead(httpConnection); %I%OHs
\7*"M y*
;:w0%>X^
byte[] b = new byte[1024]; T<u QhPMw
int nRead; 1u_< 1X3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '2S?4Z
{ p</V_BIW
nStartPos += fileAccessI.write(b,0,nRead); Uc]sWcR
//if(nThreadID == 1) `& ]H`KNa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y;>D"C..
} j55OG~)
o/I`L
*|3G"B{w6
Utility.log("Thread " + nThreadID + " is over!"); dZ,~yV
bDownOver = true; tP|ox]
//nPos = fileAccessI.write (b,0,nRead); Xm~N Bt
} %j;mDR95
catch(Exception e){e.printStackTrace ();} K,f- w2!
} SG-Xgr@
} h`V#)Q
i0{sE
b|u0a6
//打印回应的头信息 q,.@<sW
public void logResponseHead(HttpURLConnection con) Y|F~w~Cb
{ t ;bU#THM
for(int i=1;;i++) f^@DuI
{ kD_616
String header=con.getHeaderFieldKey(i); L9,O,f
if(header!=null) k'-5&Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (aSY.#;
Utility.log(header+" : "+con.getHeaderField(header)); _F tI2G9
else U3M;6j9`
break; =.t3|5U8
} >VB*Xt\C&
} !2]'S=Y
})5I/
Ydh+iLjhx
public void splitterStop() DM3 %+ xY
{ 7H_*1_%ZQ
bStop = true; xtX`3=s
} yMKVF`D*
t@3y9U$
w8(z\G_0
} E)Cdw%}^
[D<"qT^*z6
?9:~d#p
/* 2D'$
**FileAccess.java 3 UG UZ
*//文件访问(定位，写) U$wD'v3pw
package NetFox; t}f,j^`e
import java.io.*; ~cb7]^#u1l
"\l#q$1h
,2Q5'!o
public class FileAccessI implements Serializable{ i5Dq'wp
9"b =W@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9{XV=a v
RandomAccessFile oSavedFile; uN9J?j*ir
long nPos; ,?`Zrxe[
3s$vaV~(a
9<-7AN}Z
public FileAccessI() throws IOException L3'$"L.|u
{ Xx e07J~
this("",0); 3 cF4xUIZ
} 6~!l7HqO
+$\/HO
m"RSDM!
public FileAccessI(String sName,long nPos) throws IOException !6l}s$1i|
{ P,={ C6*
oSavedFile = new RandomAccessFile(sName,"rw"); ja+PVf
this.nPos = nPos; ]r(s02
oSavedFile.seek(nPos); aW;DfH
} L_Lhmtm}m
@agxu-Y
KU*XRZu)
public synchronized int write(byte[] b,int nStart,int nLen) Q;y)6+VU4
{ 3u~V&jl
int n = -1; HCZVvsG
try{ G)3Q|Vc
oSavedFile.write(b,nStart,nLen); P|QM0GI
n = nLen; 4~Jg\@
} J @^Ypq
catch(IOException e) #B!<gA$/
{ tlpTq\;
e.printStackTrace (); JbXd9AMh2
} ^H~g7&f9?N
8Ao pI3
W|AK"vf
return n; GVld]ioycG
} agp7zw=N
],l\HHQ
=a!_H=+4
} \<W/Z.}/
F6gU9=F1<
'QC'*Hl
/* 87yZd8+)
**SiteInfoBean.java Rh#QPYPq
*/ M992XXd
package NetFox; )h`8</#m{
MWJ}
e^yfoE<7
public class SiteInfoBean { b&2N7%
L^xh5{
w,eW?b
private String sSiteURL; //Site's URL Y>SpV_H%
private String sFilePath; //Saved File's Path xt1Ug~5
private String sFileName; //Saved File's Name ,j e
private int nSplitter; //Count of Splited Downloading File e)*-<AGwC
QyD(@MFxb
Ff&kK5}q
public SiteInfoBean() kV@?Oj.&I,
{//nSplitter的缺省值为5 AfvIzsT0
//default value of nSplitter is 5 sny$[!)
this("","","",5); U%rq(`;
} H_FT%`iM
;C,t`(
JiFB<Q\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &.[I}KH|B
{ <7_s'UAL!
sSiteURL= sURL; ?ZP@H _w6}
sFilePath = sPath; 2U@:.S'K
sFileName = sName; =hi{J M
this.nSplitter = nSpiltter; qijQRxS
,Rdw]O
!24PJ\~I
} o^v]d7I8b
Nj=0bg"Qg5
z^u*e
public String getSSiteURL() /B)`pF.n
{ YT}ZLx
return sSiteURL; lx:.9>
} V@r V+s
BKKW3PT
[,sm]/Xlc
public void setSSiteURL(String value) "P yG;N!W
{ cy0j>-z
sSiteURL = value; VWrb`p@
} mv>-XJ+
Scfe6+\EW
</!GU*
public String getSFilePath() E?S
{ ^j7>Ul,
return sFilePath; aRy" _dZ2
} |J$Bj?
Egmp8:nZl@
^J'O8G$
public void setSFilePath(String value) %#TAz7
{ DdqE6qE
sFilePath = value; xM=?ES
} lQ&J2H<w
&Gs/#2XQ
~rlPS#]o
public String getSFileName() !GnwE
{ g[N3jt@
return sFileName; Dg*'n
} QYc/f"9
W:hTRq
E8L\3V4
public void setSFileName(String value) lUd4`r"
{ [*1:?mD$
sFileName = value; M)3'\x:
} )v\ A8)[
'm0_pM1:D
y+h/jEbM</
public int getNSplitter() Yf_/c*t\5
{ m-]F]c=)w<
return nSplitter; p^ ONJL
} o_a'<7\#i
eW;c 3<
r4Xaa<
public void setNSplitter(int nCount) S 9|^VU
{ MavidkS
nSplitter = nCount; M[P1hFuna
} .rQcg.8/B
} N?IdaVLj
}Z)YK}_1
wRg[Mu,Q5
/* e!vWGnY
**Utility.java Zn:]?%afdO
*/ kQ"Ax? b
package NetFox; dF7`V J2
W&HxMi
(_AU)
public class Utility { z9w]{Zd_,d
poy_?7G
ZEs^b
public Utility() m -0}Pe9L
{ mQ3gp&d3W
sl`?9-_[
~( :$c3\
} KQ ^E\,@o
b^A7R{G7
//线程睡眠 2 SU
public static void sleep(int nSecond) Bf;<3k)5.
{ 1n[wk'}qf4
try{ a:s$[+'Y
Thread.sleep(nSecond); {4*5Z[
} udPLWrPF\
catch(Exception e) pm2]
{ ra8AUj~RX
e.printStackTrace (); $3xDjiBb
} *0m|`- T
} q#K0EAgC
mR$0Ij/v
//日志 |h6,.#n
public static void log(String sMsg) vhzz(UPUt
{ !Wj`U$];
System.err.println(sMsg); jOZ>^5}
} w$j6!z
_&[-< cu
%qEp{itq
public static void log(int sMsg) rNICK2Ah
{ 1Se2@WR'
System.err.println(sMsg); (:R5"|]@<x
} fi%lN_Ev?
} tMXNi\Bj
4{G>T
GK1P7Qy?V
/* =i6k[rg
**TestMethod.java OS1f}<
*/ _+Z5qUmQ
package NetFox; ^CD?SP"i
[E/. r{S
> w SI0N
public class TestMethod { n4.\}%=z
HkY#i;%N
i-.AD4
public TestMethod() V."cmtf
{ ///xx/weblogic60b2_win.exe v=cX.^L
try{ 5g.Kyj|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g ;XK3R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GyVuQ51
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?1r<`o3l\
fileFetch.start(); eI%kxqc
} &qM8)2Y
catch(Exception e){e.printStackTrace ();} (M{>9rk8
. BX*C
3QF[@8EH{
} &8I*N6p:%/
_C19eW'
T7o7t5*
public static void main(String[] args) q s:TR
{ C=2DxdZG
new TestMethod(); bf.yA:~U
} 70EH~
} wOLV?Vk
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