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)); a <C?- g|
} JOuyEPy
for(int i=0;i<nEndPos.length-1;i++) opH!sa@U
{ *;@wPT
nEndPos = nStartPos[i+1]; 1 !_p
} 1r=cCM
nEndPos[nEndPos.length-1] = nFileLength; A,F~*LXm
} OjhX:{"59
} x|m9?[ !_
l:'#pZ4T
[2-n*a(q
//启动子线程 >e {1e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c:m=9>3
for(int i=0;i<nStartPos.length;i++) ?#w} S%
{ {.2\}7.c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2yJ{B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2VRGTx
nStartPos,nEndPos,i); n5=U.r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); di/QJrw
fileSplitterFetch.start(); R `ViRJh
} #csP.z3^y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dnd; N/9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0BDw}E\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T3fQ #p
nEndPos = " + nFileLength); (ODwdN7;
// fileSplitterFetch[nPos.length-1].start(); 7_\F$bp`
P7F"#R0QB
kBZ1)?
//等待子线程结束 WGz)-IB!PE
//int count = 0; cCZp6^/<x
//是否结束while循环 ?=9'?K/~a
boolean breakWhile = false; 4`i8m
)I&.6l!#
~)f^y!PMQ
while(!bStop) ./ {79
{ FGi7KV=N
write_nPos(); U5kKT.M
Utility.sleep(500); ['o ueOg
breakWhile = true; 94-BcN
+4-T_m/W/
U,P>P+\@
for(int i=0;i<nStartPos.length;i++) Ms|c"?se
{ Qn8xe,
if(!fileSplitterFetch.bDownOver) I]C Y>'
{ 3aq'JVq
breakWhile = false; 0o+Yjg>\~8
break; o=R(DK# U
} iv>MIdIm
} _;03R{e*
if(breakWhile) ZxNTuGOB:
break; 5;}W=x^$a
EQ273sdK
0S4BV%7F
//count++; R1H^CJ=v0
//if(count>4) *#YZm>h
// siteStop(); U1r]e%df)
} ~Fuq{e9`
XY| y1L 3[
Mm$\j*f/
System.err.println("文件下载结束！"); jM\{*!7b
} &1Ndi<Y^
catch(Exception e){e.printStackTrace ();} _94 W@dW
} ??"_o3
qf(mJlU
Ef#LRcG-Z
//获得文件长度 d[_26.
public long getFileSize() pbAL&}
{ gQr+~O
int nFileLength = -1; M?lh1Yu"
try{ H<Sf0>OA
URL url = new URL(siteInfoBean.getSSiteURL()); (1'DZxJ&u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z8v8@Y
httpConnection.setRequestProperty("User-Agent","NetFox"); n.+'9Fj
wS}c\!@<,
o^/ #i`)
int responseCode=httpConnection.getResponseCode(); |@AXW
if(responseCode>=400) Y_CVDKdcY
{ V^,gpTyv*
processErrorCode(responseCode); X8*g#lO?
return -2; //-2 represent access is error N_T5sZ\
} '<o3x$6 *
4SI~y;c)
W,@F!8
String sHeader; V#oz~GMB
x{:U$[_
w!"L\QT
for(int i=1;;i++) C{bxPILw
{ &DMC\R*j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S=k!8]/d|
//Utility.log(in.readLine()); Y$L` G
sHeader=httpConnection.getHeaderFieldKey(i); +fk*c[FG
if(sHeader!=null) (%fQhQ
{ ]u5TvI,C
if(sHeader.equals("Content-Length")) Hi09?AX
{ QH-CZ6M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eJo" Z
break; {<ShUN
} Rv&"h_"t
} 6X@z(EEL
else 'u<e<hU
break; G^Gs/- f
} U"7o;q
} X_2N9$},
catch(IOException e){e.printStackTrace ();} )P(S:x'b0
catch(Exception e){e.printStackTrace ();} v8-My1toV
Lw\u{E@
uU 7 <8G
Utility.log(nFileLength); WPRk>j
;JkIZ8!
h*VDd3[#
return nFileLength; "\@J0|ppb
} 9:{<:1?
B!Wp=9)G
X)!XR/?
//保存下载信息（文件指针位置） r^ Dm|^f#
private void write_nPos() CC=I|/mBM
{ >\1twd{u]
try{ ,w~3K%B4
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1x_EAHZ>7
output.writeInt(nStartPos.length); U:*rlA@_.
for(int i=0;i<nStartPos.length;i++) :Vxt2@p{
{ fDsT@W,K
// output.writeLong(nPos); Bb=r?;zjO
output.writeLong(fileSplitterFetch.nStartPos); lf`ULY4{
output.writeLong(fileSplitterFetch.nEndPos); t5E$u(&+'B
} :XY%@n
output.close(); ~Fb@E0 }!
} |X=p`iz1&
catch(IOException e){e.printStackTrace ();} rpiuFst
catch(Exception e){e.printStackTrace ();} QKP #wR
} yc*cT%?g
9CS"s_
*B3f ry
//读取保存的下载信息（文件指针位置） ?c?@j}=?yY
private void read_nPos() qR.FjQOvn
{ C?|sQcCE
try{ k\O<pG[U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kk}, PU=
int nCount = input.readInt(); ahXcQ9jzFi
nStartPos = new long[nCount]; KRxJ2
nEndPos = new long[nCount]; G|jHic!
for(int i=0;i<nStartPos.length;i++) >l 0aME@-0
{ (/uN+
nStartPos = input.readLong(); H}r]j\
nEndPos = input.readLong(); zCJ"O9G<V
} &Z~_BT
input.close(); d[?RL&hJO
} 4vL\t uoz
catch(IOException e){e.printStackTrace ();} O + aK#eF
catch(Exception e){e.printStackTrace ();} qVh?%c1.Y
} MX]#|hEeQ
7D<Aa?cv_l
"=Z=SJ1D
private void processErrorCode(int nErrorCode) h~Ir=JV
{ |$/#,Dv7
System.err.println("Error Code : " + nErrorCode); gR!hN.I
} :WWHEZK
h.?<(I
93n%:?l"<W
//停止文件下载 B-LV/WJ_
public void siteStop() UhJS=YvT
{ lai@,_<GV
bStop = true; eM!Oc$C8[
for(int i=0;i<nStartPos.length;i++) Ly(iq
fileSplitterFetch.splitterStop(); (^~a1@f,J
K_+M?ap_
6/cm TT$i
} w(bvs&`{uC
} F7<M{h5s
//负责部分文件的抓取 _8$xsj4_
**FileSplitterFetch.java 1CJ1-]S(3
*/ Lf9s'o}.R
package NetFox; z2V ->UK)
^N7cXK*
}'vQUGu8z
import java.io.*; "zw{m+7f,
import java.net.*; |m\7/&@<
~<u\YIJ
$~q{MX&J
public class FileSplitterFetch extends Thread { jA^yUd-
N#-%b"(
-5e8m4*
String sURL; //File URL L2Cb/!z`c
long nStartPos; //File Snippet Start Position 0>m$e(Z
long nEndPos; //File Snippet End Position alRz@N
int nThreadID; //Thread's ID 5n>zJ ~
boolean bDownOver = false; //Downing is over WMKxGZg"
boolean bStop = false; //Stop identical F+G+XtOS
FileAccessI fileAccessI = null; //File Access interface 0Bgj.?l
lrPIXIM
}qGd*k0F0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0xi2VN"X
{ [2Y@O7;nI
this.sURL = sURL; 0XljFQ
this.nStartPos = nStart; D Q4O
this.nEndPos = nEnd; w?_'sP{pd
nThreadID = id; KY2z)#/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bfb9A+]3'
} nIOSP:'>
k{!9f=^
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public void run() `+."X1
{ fM& fqI
while(nStartPos < nEndPos && !bStop) BQ,749^S
{ 18~jUYMV
0WZd$
I=Y_EjZD
try{ \u6.*w5TI
URL url = new URL(sURL); N:KM8PZ&~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bvj
httpConnection.setRequestProperty("User-Agent","NetFox"); n[;)(
String sProperty = "bytes="+nStartPos+"-"; |BtFT
httpConnection.setRequestProperty("RANGE",sProperty); lt'N{LFvc
Utility.log(sProperty); [g@Uc
> B;YYj~f}
/ZL6gRRA|
InputStream input = httpConnection.getInputStream(); N3Q .4? z9
//logResponseHead(httpConnection); /&qE,>hd.+
wKpD++k
6 %`h2Z
byte[] b = new byte[1024]; xqDz*V/mD
int nRead; x!7!)]h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S]}}r)
{ P=P']\`p+
nStartPos += fileAccessI.write(b,0,nRead); 00-2u~D&
//if(nThreadID == 1) 0<<ATw$aQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 19[.&-u"
} [Ak0kH>
&\ad.O/Q
%ol1WG9
Utility.log("Thread " + nThreadID + " is over!"); D2Q0p(#%
bDownOver = true; jW^]N$>
//nPos = fileAccessI.write (b,0,nRead); Q4L7{^[X
} PgP\v-.
catch(Exception e){e.printStackTrace ();} *6}'bdQbNP
} RA){\~@wC
} j5smmtM`s
q&:%/?)x
wZ`*C mr
//打印回应的头信息 m}beT~FT_
public void logResponseHead(HttpURLConnection con) {XC[Ia6jtL
{ K|D1
for(int i=1;;i++) XQOM6$~,
{ A^|~>9
String header=con.getHeaderFieldKey(i); ^FTS'/Q
if(header!=null) (BK_A{5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M`* BS
Utility.log(header+" : "+con.getHeaderField(header)); IO2@^jup
else c:B` <
break; OeZ"WO
} jnM}N:v
} va"bw!zXo*
fL-$wK<p<
q}z`Z/`/
public void splitterStop() ]{t!J^Xn
{ 4`o<e)c3
bStop = true; 4l>d^L
} X]W(
00r7trZW^
NE Zu?g
} #\K"FE0PGz
{([`[7B>a<
*q[;-E(fZ#
/* lO0}
**FileAccess.java f)r6F JLU
*//文件访问(定位，写) j^hLn>
package NetFox; PY+4OZ$
import java.io.*; f'M([gn^_
fILvEf4b
8L6b:$Y3@C
public class FileAccessI implements Serializable{ zXbA$c
OpK_?XG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <:8Ew
RandomAccessFile oSavedFile; RU>qj *e
long nPos; !*?9n^PaF
}O| 9Qb
d..JW{
public FileAccessI() throws IOException q)AX*T+
{ -YrMVoZl
this("",0); ?a1pO#{Dg
} 7lKatk+7K
H(y Gh
@S>;t)\J
public FileAccessI(String sName,long nPos) throws IOException ]M'~uTf
{ k*Aee7
oSavedFile = new RandomAccessFile(sName,"rw"); .;l`VWP
this.nPos = nPos; `82Dm!V
oSavedFile.seek(nPos); - leYR`P
} XGjFb4Tw7
6GqC]rd*:
~03MH'
public synchronized int write(byte[] b,int nStart,int nLen) #l7v|)9v
{ ?zbWz=nq
int n = -1; wkV'']= Xg
try{ BL"7_phM,
oSavedFile.write(b,nStart,nLen); Ed2A\S6tl
n = nLen; uv^x
} HIC!:|
catch(IOException e) |k,-]c;6
{ )+w1nw|m
e.printStackTrace (); DVJn;X^T:
} {];-b0MS~
n+i=Ff
KDH<T4#x
return n; :F@goiuC
} S2nX{=
Gzg3{fXl
]]3rSXs2}J
} mZjpPlJ
=2ED w_5E
%/5Wj_|p
/* WIpV'F|t]`
**SiteInfoBean.java EbVva{;#$;
*/ 0z4M/WrNt
package NetFox; Kpa$1x
^H{YLO
o P;6i
public class SiteInfoBean { c"pOi&
sf->8
J_-fs#[x
private String sSiteURL; //Site's URL H\\FAOj
private String sFilePath; //Saved File's Path g|7o1{
private String sFileName; //Saved File's Name cCNRv$IO\
private int nSplitter; //Count of Splited Downloading File HEIg_6sb
kfT*G +l]
={V@Y-5T
public SiteInfoBean() ,]W|"NUI
{//nSplitter的缺省值为5 2lOUNxQ$
//default value of nSplitter is 5 /]MelW
this("","","",5); 0K26\1
} 6N5(DD
'%XYJr:H[
isQOt * i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OE9,D:tv
{ n-yUt72
sSiteURL= sURL; 2A[hMbL
sFilePath = sPath; 3}F>t{FDk
sFileName = sName; Jou*e%
this.nSplitter = nSpiltter; ]+W){W=ai
,w H~.LHi
WKlyOK=}
} vZ"gCf3#?3
wCruj`$
%xOxMK@
public String getSSiteURL() }&e HU
{ MJ1qU}+]
return sSiteURL; ce}A!v
} }6/M5zF3
H>+])~#
/pPHD]
public void setSSiteURL(String value) PQ[?zNrSV
{ X )tH23
sSiteURL = value; h72/03!
} 5~@-LXqL
aaT3-][
cK u[4D{
public String getSFilePath() k'#3fz\
{ iC=>wrqY>
return sFilePath; MyllL@kP
} Hy&Z0W'l
@:GqOTN
x]x3iFD
public void setSFilePath(String value) L'?aoRj
{ M-Efe_VRQc
sFilePath = value; L%is"NZh
} t~/:St
":M]3.
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public String getSFileName() sIgTSdk
{ n-cI~Ax+4
return sFileName; `hkvxt
} YYYF a
`@],J
v#%rjml[
public void setSFileName(String value) otR7E+*3
{ |<,qnf| -
sFileName = value; ZZI} Ot{
} +u0of^}=
r+E!V'{C
|xFA}
public int getNSplitter() ~rdS#f&R2
{ ZF[W<Q
return nSplitter; 1LRP R@b^
} [,AFtg[
!6=;dX
&|GH@^)@
public void setNSplitter(int nCount) M=pQx$%a
{ uhfK\.3
nSplitter = nCount; {\`ttc>
} D!,5j_,j%
} K}re{y
Q:megU'u
jsE8=zZs
/* zP #:Tv'
**Utility.java Su6kpC!EW
*/ {]]%0!n\
package NetFox; GEc-<`-
fGlvum
v9:J 55x
public class Utility { 2[+.*Ef
B+Qf?1f
EtN,
public Utility() %QEBY>|lI
{ >ceC8"}J5M
l+"p$iZs
uD=Kar
} yC\UT ~j/
z.-yL,Rc`-
//线程睡眠 Eb4NPWo
public static void sleep(int nSecond) +\Jo^\
{ it\$Pih]
try{ O~V^]
Thread.sleep(nSecond); q<q IT
} KMIe%2:b5
catch(Exception e) >=;-:
{ g:Qq%'
e.printStackTrace (); }? / Blr
} lz#.f,h
} 7gf(5p5ZV
q=88*Y
//日志 (x2?{\?
public static void log(String sMsg) q x)\{By
{ PzSLE>Q
System.err.println(sMsg); {TNORbZz
} e7;7TrB.
:KO&j"[
j;`Q82V\
public static void log(int sMsg) #Pg`0xiV
{ !VWA4 e!+
System.err.println(sMsg); I~n4}}9M
} .J O3#
} gdf0
gxVr1DIkN
$uTrM8
/* q1:dcxR[
**TestMethod.java K^fs#7
*/ hO8xH +;
package NetFox; 1<_][u@
1(BLdP3&
62R";# K
public class TestMethod { ,:(s=JN+
C;m"W5+
H^n@9U;[K
public TestMethod() wkZwtq
{ ///xx/weblogic60b2_win.exe ,gQl_Amvz
try{ uxTgK'3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i0{\c}r:4b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2(DhKHrF
SiteFileFetch fileFetch = new SiteFileFetch(bean); CHKhJ v3+4
fileFetch.start(); 8C*@d_=q
} WBWW7HK
catch(Exception e){e.printStackTrace ();} ]?=87w
,1mL=|na
C7{VByxJ
} SDC|>e9i
t7-]OY7%w_
jI\@<6O
public static void main(String[] args) _ZhQY,
{ 5]Rbzg2t
new TestMethod(); akyMW7'3V<
} ~_EDJp1J
} +I3Vfv
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