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)); $ 64up!
} >B6*`3v
for(int i=0;i<nEndPos.length-1;i++) ,ayEZ#4.m
{ !=eNr<:V.
nEndPos = nStartPos[i+1]; r#OPW7mhE
} .e7tq\k
nEndPos[nEndPos.length-1] = nFileLength; lqfTF
} loIb}8
} N# }A9t
+j{Cfv$do
=!t;e~^8]
//启动子线程 x`g,>>&C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H$Kc~#=
for(int i=0;i<nStartPos.length;i++) :(]fC~G~
{ H^|TV]^;N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), + ,Krq 3P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0!,uo\`
nStartPos,nEndPos,i); 36Lkcda[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =p_*lC%N
fileSplitterFetch.start(); "}v.>L<P
} ktrIi5B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Go{,< gm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i2Wvu3,D3-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V22z-$cb
nEndPos = " + nFileLength); xnMcxys~
// fileSplitterFetch[nPos.length-1].start(); R ABw(b
8)>x)T
(ODwdN7;
//等待子线程结束 JwbZ`Z*w
//int count = 0; ]JkEf?;.
//是否结束while循环 KAnV%j
boolean breakWhile = false; jh/,G5RM9
BP9#}{kE
%rb$tKk
while(!bStop) ~yJ2@2I
{ d%|l)JF*5
write_nPos(); b=r3WkB6
Utility.sleep(500); X8ulaa
breakWhile = true; d#E&,^@M
}gQ2\6o2g
Rq}lW.<r
for(int i=0;i<nStartPos.length;i++) {3x>kRaKci
{ o*)Sg6Yk
if(!fileSplitterFetch.bDownOver) ynmjIQ
{ - ]wT
breakWhile = false; p?f\/
break; [uU!\xe
} '?Dxe B
} ;~<To9O
if(breakWhile) KFbB}oId
break; 3'.@aMA@
bVUIeX'
n/skDx TE
//count++; #B5,k|"/,M
//if(count>4) %]Z4b;W[Y
// siteStop(); 6 ]x?2P%
} .yy-jf/
qA GjR!=^
]P3m=/w
System.err.println("文件下载结束！"); ^i%S}VK
} v\,N"X(,
catch(Exception e){e.printStackTrace ();} eMRH*MyD
} i#V(oSx
Fs~(>w@
0cycnOd
//获得文件长度 m}'_Poc
public long getFileSize() XX/gS=NE#.
{ ZHK>0>;
int nFileLength = -1; ;Xt<\^e
try{ %[$HX'Y
URL url = new URL(siteInfoBean.getSSiteURL()); 7,SQz6]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !vnC-&G
httpConnection.setRequestProperty("User-Agent","NetFox"); cR3d&/_,U
a6LL]_&g
\o!3TK"N
int responseCode=httpConnection.getResponseCode(); #`u}#(
if(responseCode>=400) 96^aI1:
{ lndz
processErrorCode(responseCode); N_T5sZ\
return -2; //-2 represent access is error ~`AB-0t.u
} w~u{"E$
8Nzn%0(Q
|4mvB2r
String sHeader; g.&B8e
Q!P%duO
6axxyh%
for(int i=1;;i++) \!\:p/f
{ 0 SSdp<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b11I$b #
//Utility.log(in.readLine()); K[y")ooE<j
sHeader=httpConnection.getHeaderFieldKey(i); vR\E;V
if(sHeader!=null) w||t3!M+n
{ D<J'\mo
if(sHeader.equals("Content-Length")) 8lV:-"+5
{ t.ulG *
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M>i(p%
break; ? uYO]!VC
} ;NA5G:eQ
} `9r{z;UQ
else )5b_>Uy
break; \( s `=(t
} hTDGgSG^
} ya&=UoI
catch(IOException e){e.printStackTrace ();} >B{qPrmI
catch(Exception e){e.printStackTrace ();} w<H Xe
"\@J0|ppb
@4;'>yr(
Utility.log(nFileLength); ?1ey$SSU]
sLA.bp.O
QDn_`c
return nFileLength; E,m|E]WP
} ]ltCJq
Z+k) N
aA4RC0'
//保存下载信息（文件指针位置） j9k:!|(2'
private void write_nPos() lWc[Q1
{ nDvfb*\
try{ sc]#T)xG
output = new DataOutputStream(new FileOutputStream(tmpFile)); qefp3&ls
output.writeInt(nStartPos.length); Gt*<Awn8
for(int i=0;i<nStartPos.length;i++) :z8/iD y
{ >3/mV<g f
// output.writeLong(nPos); 'f{13-#X@
output.writeLong(fileSplitterFetch.nStartPos); \uTlwS
output.writeLong(fileSplitterFetch.nEndPos); {LiJ=Ebt
} c6F?#@?
output.close(); C[,h!
} ,&,%B|gT]
catch(IOException e){e.printStackTrace ();} 1R}9k)JQ
catch(Exception e){e.printStackTrace ();} n=-vOa%
} (LK@w9)i;
!U?C_
X.#*+k3s0
//读取保存的下载信息（文件指针位置） !ldEy#"X
private void read_nPos() _qE9]mU
{ F qJ`d2E
try{ h1q3}-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -F/)-s6#!'
int nCount = input.readInt(); jlb8<xIC]
nStartPos = new long[nCount]; M;XU"8
nEndPos = new long[nCount]; _kBmKE
for(int i=0;i<nStartPos.length;i++) n}Z%-w$K#
{ P\dfxR;8%
nStartPos = input.readLong(); BW;@Gq@N
nEndPos = input.readLong(); #!_4ZX
} ulALGzPh
input.close(); \'=svJ
} P6%qNR/ x
catch(IOException e){e.printStackTrace ();} $|7"9W}m*
catch(Exception e){e.printStackTrace ();} VJ#ys_W
} tfHr'Qy BC
nrE.0Ue1
b6S"&hs
private void processErrorCode(int nErrorCode) ozsd6&z5l
{ r } Wdj
System.err.println("Error Code : " + nErrorCode); `}t5`:#k
} NdJ]\>5oN,
\ 3E%6L
\#biwX
//停止文件下载 8cfsl lI
public void siteStop() yE N3/-S+
{ I8i|tQz
bStop = true; V #vkj
for(int i=0;i<nStartPos.length;i++) /QS Nv
fileSplitterFetch.splitterStop(); 5q4wREh
+9LzDH
j(I(0Yyh
} %J6>Vc!ix=
} Ox ,Rk
//负责部分文件的抓取 [.l,#-vp
**FileSplitterFetch.java Y|mtQE?c
*/ 0;a10b
package NetFox; !JdZ0l
0Bgj.?l
a:P+HU:
import java.io.*; \gT({XU?
import java.net.*; q !}~c
vZQraY nJ
R,.qQF\*
public class FileSplitterFetch extends Thread { R{H8@JLD
uWMSn
.HTRvE`X
String sURL; //File URL k_1;YOBF
long nStartPos; //File Snippet Start Position BV<_1WT}
long nEndPos; //File Snippet End Position Foj|1zJS_
int nThreadID; //Thread's ID maSVqG
boolean bDownOver = false; //Downing is over UH&1QV
boolean bStop = false; //Stop identical kb$Yc)+R4
FileAccessI fileAccessI = null; //File Access interface <bJ|WS|
"WY5Pzsi:
V9KRA 1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9Pvv6WyKy
{ [#aJ- Uu
this.sURL = sURL; \Dr( /n
this.nStartPos = nStart; Md9y:)P@Y
this.nEndPos = nEnd; b$Ei>%'/";
nThreadID = id; y:zNf?6&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B!x6N"
} BQ,749^S
f^}n#
OGH,K'l
public void run() '4GN%xi
{ BC#`S&R
while(nStartPos < nEndPos && !bStop) :V6t5I'_
{ ?;w`hA3ei
\u6.*w5TI
#3>jgluM'
try{ ^0{t
URL url = new URL(sURL); Kl?C[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WOgkv(5KN
httpConnection.setRequestProperty("User-Agent","NetFox"); Nj?Q{ztS
String sProperty = "bytes="+nStartPos+"-"; Ei2M~/
httpConnection.setRequestProperty("RANGE",sProperty); #$ka.Pj
Utility.log(sProperty); sWTa;Qi
VeEa17g&
,<7HLV
InputStream input = httpConnection.getInputStream(); `p)U6J
//logResponseHead(httpConnection); D0_CDdW%7
/ZL6gRRA|
!Qsjn
byte[] b = new byte[1024]; 3:w_49~:~
int nRead; |A|K);
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )yz)Fw|&
{ Bs '=YK$
nStartPos += fileAccessI.write(b,0,nRead); kTzO4s?
//if(nThreadID == 1) [@pumH>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `S3)uV]I
} QXa2qxTc
zk@s#_3ct
x!7!)]h
Utility.log("Thread " + nThreadID + " is over!"); mWP&N#vwh
bDownOver = true; 6c>:h)?
//nPos = fileAccessI.write (b,0,nRead); r0OP !u
} ^VnnYtCRz
catch(Exception e){e.printStackTrace ();} 71IM`eL=ED
} ^IvQdVB
} 0<<ATw$aQ
9%Vy,
>CcDG
//打印回应的头信息 c[3x>f0
public void logResponseHead(HttpURLConnection con) klc$n07
{ L[5U(`q[
for(int i=1;;i++) 'aeuL1mz
{ P~&J@8)c
String header=con.getHeaderFieldKey(i); Aj/EaIq
if(header!=null) 5)rN#_BKj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :Ez*<;pF'
Utility.log(header+" : "+con.getHeaderField(header)); }0/l48G
else cl{mRt0
break; FUL'=Xo
} M`9|8f,!a
} |<8Fa%!HHc
1(i%nX<U
_K!)0p
public void splitterStop() 1'\s7P
{ -) +B!"1
bStop = true; }t|i1{%_
} BNO+-ob-
s`yg?CR`,
N]ebKe
} WXf[W
LF{8hC[
m}beT~FT_
/* ^mut-@ N9
**FileAccess.java !F Zg' 9
*//文件访问(定位，写) C0^r]^$Z
package NetFox; $EdL^Q2KAy
import java.io.*; fU.z_T[@
(_N(K`4#W
! P$[$W
public class FileAccessI implements Serializable{ pz{ ]O_px
&:}WfY!hX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #g2&x sU
RandomAccessFile oSavedFile; lG[j,MDs
long nPos; (b1e!gJpy
n0V^/j}
UuZjf9}
public FileAccessI() throws IOException S*76V"")
{ +'VYqu/
this("",0); 0hXx31JN N
} >I;.q|T
p%#'`*<a_
w xaMdA
public FileAccessI(String sName,long nPos) throws IOException 3".#nN
{ D mky!Cp
oSavedFile = new RandomAccessFile(sName,"rw"); l&Y'5k_R
this.nPos = nPos; rodqa
oSavedFile.seek(nPos); IF6-VFY:6
} @W,<8
<<Z, 1{3F
>$a;+v
public synchronized int write(byte[] b,int nStart,int nLen) g<$2#c}
{ I;UT;/E2
int n = -1; Q^xk]~G$(
try{ HHs!6`R$0c
oSavedFile.write(b,nStart,nLen); e;|$nw-
n = nLen; XBcbLF
} B)P]C5KRD
catch(IOException e) v5{2hCdt
{ U+["b-c
e.printStackTrace (); *q[;-E(fZ#
} eq<!
Jy('tfAHp
hL}ZPHA
return n; cT;Zz5
} *|@386\
$e uI
PY+4OZ$
} Qf'g2 \
)NqRu+j
8NJT:6Q7l
/* $(*>]PC+)
**SiteInfoBean.java `'pAiu
*/ a#9pN?~
package NetFox; p|BoEITL
%E [HMq<H
U: )Gc
public class SiteInfoBean { k7cY^&o
^oW{N
zW)Wt.svP
private String sSiteURL; //Site's URL &$l#0?Kc^
private String sFilePath; //Saved File's Path M23r/eg]
private String sFileName; //Saved File's Name sN#ju5
private int nSplitter; //Count of Splited Downloading File $>+g)
kZi/2UA5Z
dB:c2
public SiteInfoBean() iHvWJ<"jR
{//nSplitter的缺省值为5 MhB>bnWXR
//default value of nSplitter is 5 (S?DKPnR
this("","","",5); uotW[L9
} }-u%6KZ
cF?0=un
)V_;]9<wt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B$hog_=s
{ t-<BRnxhE
sSiteURL= sURL; {lgiH+:
sFilePath = sPath; ,]Xn9W
sFileName = sName; o-;/x)
this.nSplitter = nSpiltter; +F2X2e)g"
|y+_BZ5
x]3[0K5;
} ]IzD`
33&\E- Q>
_c5*9')-)
public String getSSiteURL() ,@Kn@%?$
{ Hk(=_[S
return sSiteURL; sNP ;
} ( 5uSqw&U
(Fq:G) $
9b@yDq3hQ
public void setSSiteURL(String value) tE-g]y3
{ 1xh7KBr,
sSiteURL = value; t%<y^Wa=
} <$WS~tTz
dep"$pys>
j0(jXAc;UB
public String getSFilePath() J(wFJg\/
{ m -hZ5i
return sFilePath; 8%xBSob{j
} 1-&L-c.
?ks.M'@
}6=)w@v
public void setSFilePath(String value) A5%$<
{ ,H^!G\
sFilePath = value; brlbJFZ19
} ED>a'y$f
y*v|q=
>7S@3,C3ke
public String getSFileName() ]0j_yX
{ !]RSG^%s{
return sFileName; Nd{U|k3pL
} a;M{-G
Fop +xR,Z
,LxkdV
public void setSFileName(String value) TU*EtE'g/
{ bX`Gv+
sFileName = value; &|db}\jT
} 2% OAQ(
()F{kM8
1xkrhqq
public int getNSplitter() ZmNNR 1%/
{ p(8@
return nSplitter; *c&|2EsZ
} x}V&v?1{5
^H{YLO
U%[ye0@:
public void setNSplitter(int nCount) lBAu@M
{ m]vV.pwv
nSplitter = nCount; fFWi 3.
} Hrph>v
} 6 .)Xeb"
ffBd
AQT_s9"0
/* bovAFdHW
**Utility.java L[,19;(
*/ u]9\_{c]Q
package NetFox; sowwXrECg@
qMA-#
*f`P7q*
public class Utility { \g h |G
_L$a[zH
2CneRKQy
public Utility() i. (Af$
{ n|XheG7:
<JU3sXl
slUi)@b
} -B&(&R
gZ7R^] k
//线程睡眠 UxzF5V5
public static void sleep(int nSecond) 2Q5@2jT
{ Hbd>sS
try{ c;fLM`{*
Thread.sleep(nSecond); 7v)p\#-
} kc't
catch(Exception e) X0$q!
{ v+W'0ymbnV
e.printStackTrace (); N'R^gL
} +*?l">?|F
} }2Euz.0
\=bKuP(it
//日志 lw.[qP
public static void log(String sMsg) ;l ZKgi8`
{ Fb=uN
System.err.println(sMsg); |?8nO.C~V
} DL1nD5
!4'Fz[RK
v^8sL` F
public static void log(int sMsg) UeLO`Ug0;
{ @z{SDM
System.err.println(sMsg); 7bihP@I!
} yb?Pyq.D
} Hz2Sx1.i
J'$NBws
'xGhMgR;
/* *Q/^ib9=
**TestMethod.java /#H P;>!n
*/ =\5WYC
package NetFox; G[yzi
hr6j+p:
}&e HU
public class TestMethod { MJ1qU}+]
tZz%x?3G
]rH[+t-
public TestMethod() ?X@[ibH6
{ ///xx/weblogic60b2_win.exe H?J:_1
try{ _#6Qf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9&AO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ohp@ZJ!a?
SiteFileFetch fileFetch = new SiteFileFetch(bean); _lwKa,}
fileFetch.start(); a*U[;(
} jTIG#J)
catch(Exception e){e.printStackTrace ();} ~$5XiY8A
*qy \%A
9n{Y6I x:
} dX@ic,?
;M4[Liw~O
c&',#.9
public static void main(String[] args) L'?aoRj
{ M-Efe_VRQc
new TestMethod(); &um++ \
} t~/:St
} m1Ya
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