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)); q-8 GD7
} nf G:4k,
for(int i=0;i<nEndPos.length-1;i++) 9wb$_j]F`#
{ @g=A\2
nEndPos = nStartPos[i+1]; ^3yjE/Wi"
} n'h )(^
nEndPos[nEndPos.length-1] = nFileLength; w\2[dd
} r2H'r ,N
} rP\7C+
<0LB]zDWe6
wFd*6%
//启动子线程 -=sxbs.aA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \A~ '&
for(int i=0;i<nStartPos.length;i++) ~V|!\CB
{ <s7{6n')
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g<dCUIbcQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~!nd'{{9
nStartPos,nEndPos,i); #U_u~7?H$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z~Pmh%b
fileSplitterFetch.start(); ``E;!r="v
} fVN}7PH7+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $cy:G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /pge7P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,/ig8~u'c
nEndPos = " + nFileLength); AeJM[fCMa
// fileSplitterFetch[nPos.length-1].start(); f%}+.eD
jN<]yhqf
QNtr=
//等待子线程结束 bn(Scl#@K
//int count = 0; ?rK%;GTo
//是否结束while循环 =J'?>-B
boolean breakWhile = false; p.\KmEx
C1do]1VH
.6;B3
while(!bStop) GB+d0 S4
{ &T|-K\*
write_nPos(); zg j35
Utility.sleep(500); Yptsq@s
breakWhile = true; LK%B6-;~-
=Ffq =<
G_<[sMC8
for(int i=0;i<nStartPos.length;i++) ~^C7(g )
{ Kk(ucO
if(!fileSplitterFetch.bDownOver) cU6#^PFu
{ E0hp%:
breakWhile = false; s*X\%!l9
break; Iw:("A&~
} v}Nx*%
} $^XPk#$m
if(breakWhile) ["IJh
break; '_<`dzz
9]w0zUOL6
^U?(g0<"
//count++; 9M=K@a
//if(count>4) WuQYEbap
// siteStop(); 8{l=`y"nB
} .0-m=3mp2
ykeUS zz2
? 7EVmF
System.err.println("文件下载结束！"); d&u/7rm
} 4a|Fx
catch(Exception e){e.printStackTrace ();} '9dtIW6E
} N9PM.nbd%
[-gKkOT8E
<khAc1"
//获得文件长度 UmE{>5Pt
public long getFileSize() \|t0~sRwh
{ y~=hM
int nFileLength = -1; >PVi 3S
try{ @[RY8~
URL url = new URL(siteInfoBean.getSSiteURL()); 614/wI8(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9"RfL7{
httpConnection.setRequestProperty("User-Agent","NetFox"); 6V?RES;X
XOwMT,=Z)
"poTM[]tZ7
int responseCode=httpConnection.getResponseCode(); xwxjj
if(responseCode>=400) z{jAt6@7
{ D5b_m|7%
processErrorCode(responseCode); kZ}u
return -2; //-2 represent access is error PPO<{
} g DG m32
NGs9Jke2
TjK5UML
String sHeader; 90ag!
jq)|7_N
}_22wjm~
for(int i=1;;i++) Ve1] ECk
{ IpXhb[UZ?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EM/+1 _u
//Utility.log(in.readLine()); z{0;%E
sHeader=httpConnection.getHeaderFieldKey(i); t g*[%Jf^
if(sHeader!=null) \>`$x:
{ K-C,+eI
if(sHeader.equals("Content-Length")) g0OS<,:
{ ,b(S=r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,O)\,tg
break; ZcRm5Du~:
} ;_aoM&
} F\rSYjMyk
else 7YjucPH#
break; [s{:}ZuKc
} f4T0Y["QA
} .6F3;bg R7
catch(IOException e){e.printStackTrace ();} I?g__u=n~
catch(Exception e){e.printStackTrace ();} h}>/Z3*
Kn$1W=B1.
] *VF Ws
Utility.log(nFileLength); da'E"HN@G~
X/Rx]}[
5)5bt q)[
return nFileLength; M9g\/]Io;
} |I5?5 J\
s)8M? |[`I
%,cFX[D/)
//保存下载信息（文件指针位置） 5a!e%jj
private void write_nPos() PB67?d~
{ yN<fmi};c
try{ VFSn!o:C
output = new DataOutputStream(new FileOutputStream(tmpFile)); J_E(^+
output.writeInt(nStartPos.length); f}Tr$r
for(int i=0;i<nStartPos.length;i++) xt,L* B
{ ~*c=
// output.writeLong(nPos); ^p zxwt
output.writeLong(fileSplitterFetch.nStartPos); 0P40K
output.writeLong(fileSplitterFetch.nEndPos); TK/'=8
} W.D3$
output.close(); %N>NOk)
} { DQE7kI
catch(IOException e){e.printStackTrace ();} ~o'#AP#N~
catch(Exception e){e.printStackTrace ();} 9Pp|d"6]y
} M6*{#Y?
X7d.Ie
fP1OH&Ar
//读取保存的下载信息（文件指针位置） s8d}HI
private void read_nPos() ?EQ^n3U$
{ nCMa$+
try{ z12But\<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X5|/s::u
int nCount = input.readInt(); wy- C~b'Qd
nStartPos = new long[nCount]; qZsddll
nEndPos = new long[nCount]; >[fVl8G_0
for(int i=0;i<nStartPos.length;i++) G0 /vn9&
{ HU[nN*
nStartPos = input.readLong(); {Y:ZY+
nEndPos = input.readLong(); mhLRi\[c )
} Rw\C0'
input.close(); _+04M)q0
} ?wf+{x-dPP
catch(IOException e){e.printStackTrace ();} _6UAeZ*M
catch(Exception e){e.printStackTrace ();} 5Vo}G %g
} ;;'a--'"
t?nc0;Q9,@
m_"p$m;
private void processErrorCode(int nErrorCode) 1uS-Tx
{ )Ct*G= N
System.err.println("Error Code : " + nErrorCode); GP[r^Z
} (5q%0|RzRs
RYZE*lWUh
soq".+Q
//停止文件下载 qm}>J^hnB#
public void siteStop() +Sd,l>8\
{ ? TT8|Os
bStop = true; yb4tJu$
for(int i=0;i<nStartPos.length;i++) IiK(^:~%
fileSplitterFetch.splitterStop(); #>:(#^Uu
yLz,V}
)Bn>/-
} z34>,0
} ^~6]0$yJ
//负责部分文件的抓取 #xP!!.DF(
**FileSplitterFetch.java !b]2q%XM
*/ "?SOBA!vy
package NetFox; jfY{z=*]u
q|u8CX
/"Yx@n
import java.io.*; TA0D{
import java.net.*; x1BOW
GX@W"y
N8XC~Dh{
public class FileSplitterFetch extends Thread { J,1osG<6x
&6t3SZV
a}Fkx
String sURL; //File URL -N7xO)
long nStartPos; //File Snippet Start Position k?HrD"k"
long nEndPos; //File Snippet End Position f' '{.L
int nThreadID; //Thread's ID mUt,Z^ l`
boolean bDownOver = false; //Downing is over -H4+ur JJ
boolean bStop = false; //Stop identical =\Vu=I
FileAccessI fileAccessI = null; //File Access interface kWs+2j
^V: "zzn&
?cO8'4 bq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L8dU(P
{ l7'{OB L
this.sURL = sURL; o3F|#op
this.nStartPos = nStart; ``|gcG
this.nEndPos = nEnd; d=?Mj]
nThreadID = id; 3Rd`Ysp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jh\:X<q
} j6e}7
g8,?S6\nMz
^S#\O>GHP
public void run() ~#x:z^U
{ NuD[-;N]
while(nStartPos < nEndPos && !bStop) "brRME3
{ }. xrJ52Tz
SH vaV[C
;vJ\]T ml
try{ _V& !4Zd9:
URL url = new URL(sURL); Ns2,hQFc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `c'
httpConnection.setRequestProperty("User-Agent","NetFox"); $U>/i@D
String sProperty = "bytes="+nStartPos+"-"; v]:+`dV
httpConnection.setRequestProperty("RANGE",sProperty); ;+i'0$;*w
Utility.log(sProperty); DikdC5>O>m
TX23D)CX
xJ~ gT
InputStream input = httpConnection.getInputStream(); `S\zqF<
//logResponseHead(httpConnection); ^Ti_<<X
-^iUVO`z
$Ns,ts(ng
byte[] b = new byte[1024]; J%\- 1
int nRead; AfRW=&xdT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _%'L@[ H
{ 2~!R*i
nStartPos += fileAccessI.write(b,0,nRead); R<;OEN
//if(nThreadID == 1) x6^l6N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2e9jo,i
} Zk=*7?!!
<)O>MI' 4
C,A!tj7@
Utility.log("Thread " + nThreadID + " is over!"); > -y&$1
bDownOver = true; T-|9o|~z
//nPos = fileAccessI.write (b,0,nRead); MzQ\rg_B7
} #wenX$UTh3
catch(Exception e){e.printStackTrace ();} UvxSMD:A
} qKdS7SoS
} N0Efw$u
Vi|7%!j<
HDmx@E.@
//打印回应的头信息 M18qa,fK{
public void logResponseHead(HttpURLConnection con) +Edzjf~Tt
{ 9u,8q:I.?
for(int i=1;;i++) G'f9N^w
{ <4bz/^
String header=con.getHeaderFieldKey(i); j8GY`f#
if(header!=null) E6Q]A~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -<qxO
Utility.log(header+" : "+con.getHeaderField(header)); :dP~.ZY7
else SY-ez91
break; i;o}o*=
} $Y6I_U
} {L@+(I
0K<x=-cCB
,~4H{{<j
public void splitterStop() X^}A*4j
{ Rj[hhSx 2
bStop = true; TUh&d5a9H
} ]^=|Zd-
qib7Z]j
KRYcCn
} fb\DiKsW
ugYw<
Ji;SY{~kv
/* ]3*P:$Rq
**FileAccess.java ha*X6R
*//文件访问(定位，写) ~>V-*NT8
package NetFox; #s"851e
import java.io.*; q|5Q?t:,r
5|ic3
N.Dhu~V
public class FileAccessI implements Serializable{ *E:x E/M!2
qmZ2d!)o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o+nG3kRD
RandomAccessFile oSavedFile; GCT@o!
long nPos; D+Cm<ZT~
aG%kmS&fv
5m4DS:&
public FileAccessI() throws IOException !(Krf
{ b"``D ?
this("",0); KP3n^ $~
} x97L6!
Lf. 1>s
JqEW=5
public FileAccessI(String sName,long nPos) throws IOException u~W{RHClW
{ OifvUTl9b
oSavedFile = new RandomAccessFile(sName,"rw"); mN;+TN'?{
this.nPos = nPos; iq?l#}]
oSavedFile.seek(nPos); eNRs&^
} !X|k"km"
{<2>6 _z
hd B |#t
public synchronized int write(byte[] b,int nStart,int nLen) #,L~w
{ 7^$)VBQ/
int n = -1; XS?gn.o\
try{ "PMQyzl
oSavedFile.write(b,nStart,nLen); +t98@
n = nLen; DkgUvn/S
} mEFw|M{
catch(IOException e) Yd:Q`#7A
{ f1mHN7hxW
e.printStackTrace (); !VwmPAMr#v
} y4@gGC=
$Pxb1E
d?A}qA[(
return n; -v+&pG?m
} +2RNZEc
fW?sYC'
~,"N[Q
} B8T\s)fxnX
?}}qu'N:N
2j&v;dmh<
/* 8d!GZgC8R
**SiteInfoBean.java Qzqc .T
*/ a+`D'?z
package NetFox; PWH^=K
=E(#YCx
Z) Wnow
public class SiteInfoBean { `0bP0^w
]f8L:=c
PU1,DU
private String sSiteURL; //Site's URL h[kU<mU"T
private String sFilePath; //Saved File's Path x5}lgyt
private String sFileName; //Saved File's Name )I`if(fG
private int nSplitter; //Count of Splited Downloading File rn8cdMN
xzsdG?P
IA4N@ijRxh
public SiteInfoBean() .2W"w)$nuq
{//nSplitter的缺省值为5 mT@nn,
//default value of nSplitter is 5 n[,XU|2
this("","","",5); |a-fE]{7
} 6)qp*P$L
rh!;|xB|+
7"4z+w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -)v@jlg02
{ +5!&E7bcd
sSiteURL= sURL; {u"8[@@./
sFilePath = sPath; :@eHX&
sFileName = sName; ST1'\Eo
this.nSplitter = nSpiltter; s$w;q\1z
Vi?q>:E:
z.36;yT/
} X^s2BW
o(!@7Lqq
a~PK pw2%
public String getSSiteURL() ;f1qLI
{ xb:&(6\F
return sSiteURL; }^xE|~p
} X(@uwX$m
-MBV$:_R
D`[Khsf
public void setSSiteURL(String value) d$t40+v
{ s@8w-]"
sSiteURL = value; -TO\'^][X
} w_hHfZ9E
ALc`t(..}A
a0=WfeT
public String getSFilePath() T 2F6)e
{ tyh@^7
return sFilePath; %eg+F
} H,QTYXi "
y7/F_{
j$Ab>}g]
public void setSFilePath(String value) @n-r-Q
{ )5_jmW`n
sFilePath = value; S<`I Jpkv
} !cSq+eD
- +>1r
:o46rBs
public String getSFileName() q?):oJ
{ KC`q#&dt
return sFileName; */^QH@P
} cPDQ1qre!
`R"~v/x
jYRP8 Yi
public void setSFileName(String value) :9|\Z|S(I
{ _oG&OJ@
sFileName = value; bq>_qpr
} b2,!g }I
g[H',)A)
nKoiG*PI
public int getNSplitter() |~!U4D\
{ t]aea*B
return nSplitter; qIIJ4n
} 0@I S
H+E$:)gN
\C,p WW
public void setNSplitter(int nCount) _P?s'HH
{ vi.w8>CE
nSplitter = nCount; |`TgX@,#9
} En{`@JsM
} 1rKy@9
M_g?<rK
@$9'@")
/* F$BbYf2i
**Utility.java V#REjsf,t-
*/ #@HF<'H}mu
package NetFox; $+p?Y)h .
LbEM^D
UT0){%2@
public class Utility { [NMVoBvG
u .f= te
21hv%CF\9
public Utility() ^XbU~3(
{ }}v9 `F
6AG`&'"
1#IlWEg
} I/Jb!R ~
|a1{ve[
//线程睡眠 ~5FW[_
public static void sleep(int nSecond) I[)%,jd
{ mKrh[nA
try{ h2ytS^
Thread.sleep(nSecond); 7frTTSZ
} %\]*OZ7
catch(Exception e) )e5 @
{ wLK07e(
e.printStackTrace (); (e(:P~Ry
} <-D/O$q
} ^8.]d~j
YIw1
//日志 ~ab:/!Z
public static void log(String sMsg) T,aW8|
{ $9Hcdbdm
System.err.println(sMsg); fhL,aCS=
} Pj}66.
VD_$$Gn*q
-py@DzK
public static void log(int sMsg) FEVEp
{ PDs@?nz,
System.err.println(sMsg); $Y69@s%f
} ;)N>t\v
} wF((
(=7Cs
9$2/MT't
/* 0a80 LAK
**TestMethod.java th;{V%:LW
*/ &=VDASEu
package NetFox; ^R:cd8+?%
"[y-+)WTG
g+J-Zg6
public class TestMethod { 0u\GO;
y;s`P.
~\J}Kqg
public TestMethod() tH-C8Qxy
{ ///xx/weblogic60b2_win.exe ,^uEYT}j
try{ RzWXKBI\E]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w.[ "p9tc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;q*e=[_DF
SiteFileFetch fileFetch = new SiteFileFetch(bean); M5 <@~V/[
fileFetch.start(); : |>Gc39`t
} +E{|63~q
catch(Exception e){e.printStackTrace ();} s&RVJX>Rt
6Vz9?puD
\[y`'OD~
} PYGRsrcFd#
)jt #=9ZQ
A!h`]%0B
public static void main(String[] args) D8$G`~hD
{ @nux9MX<9
new TestMethod(); v%q0OX>9X"
} <yd{tD$A*
} 3\XU_Xs(]
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