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)); 2A|6o*s"
} uyj*v]AE'
for(int i=0;i<nEndPos.length-1;i++) }0RFo96)v
{ u'1=W5$rK
nEndPos = nStartPos[i+1]; !?/bK[ P,
} :nUsC+oBS
nEndPos[nEndPos.length-1] = nFileLength; bicL%I2h
} JUFO.m^w
} "r"An"
|lwN!KVQ,
JrTBe73.]j
//启动子线程 fZfiiE~7J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M3 u8NRd5|
for(int i=0;i<nStartPos.length;i++) 5I,X#}K[
{ ew$Z5N:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AHY)#|/)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y3]"H(
nStartPos,nEndPos,i); %ko 8P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mU$7_7V~
fileSplitterFetch.start(); vKC&Qi ;
} %Qz`SO8x?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #UD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DG?\6Zh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vP?S0>gh
nEndPos = " + nFileLength); #.YcIR)
// fileSplitterFetch[nPos.length-1].start(); );DIrA
2kq@*}ys
s.)w A`&&
//等待子线程结束 T+h{Aeg
//int count = 0; %iC63)(M
//是否结束while循环 Gx_e\fe-/
boolean breakWhile = false; U&$]?3?
nV*sdSt
iQC&d_#
while(!bStop) ss8v4@C
{ SVh4)}.x
write_nPos(); 2z# @:Q
Utility.sleep(500); /exl9Ilt]
breakWhile = true; 2(//slP
F|`B2Gr
Ki6.'#%7
for(int i=0;i<nStartPos.length;i++) NV4W2thYo
{ /,Id_TTCO
if(!fileSplitterFetch.bDownOver) bnu0*Zg>
{ gGml c:/J%
breakWhile = false; k.[) R@0%
break; Jjh!/pWZ4
} &(^u19TKl
} X]"OW
if(breakWhile) ^>{;9lo<
break; VDjIs UUX
+/86w59
1|w:xG^
//count++; ?Hxgx
//if(count>4) q.[[c
// siteStop(); A!Ct,%
} k]9>V@C
6_K#,_oZ
aEdJri
System.err.println("文件下载结束！"); >/kG5]zxY
} %]$p ^m
catch(Exception e){e.printStackTrace ();} @SG"t,5s
} +u:OAsR
"gajBY
FXEfD"
//获得文件长度 DK_v{R
public long getFileSize() u!Nfoq&'u
{ V?dK*8s
int nFileLength = -1; ]J=)pDrk
try{ /1#Q=T
URL url = new URL(siteInfoBean.getSSiteURL()); xWe1F2nY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vP)~j1
httpConnection.setRequestProperty("User-Agent","NetFox"); Rn_W|"
lT!$\E$1
x&oBO{LNK,
int responseCode=httpConnection.getResponseCode(); ^_h7!=W
if(responseCode>=400) wK`ieHmp
{ `Mp7})
processErrorCode(responseCode); M#=5u`h
return -2; //-2 represent access is error ~2DV{dyj
} a;T[%'in
y{I[}$k
8 E+C:"
String sHeader; 8Pr7aT:,
#L= eK8^e
iA{jKk=
for(int i=1;;i++) r5da/*G/O
{ ~G:2iSi(#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v[DbhIXU
//Utility.log(in.readLine()); *[~o~e/YCb
sHeader=httpConnection.getHeaderFieldKey(i); C5PBfn<j
if(sHeader!=null) nC.2./OwMf
{ !v4j`A;%
if(sHeader.equals("Content-Length")) bKJ7vXC05
{ yO,`"Dc_0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S<]a@9W
break; zpr@!76
} C9Z\G 3
} n.XhK_6n]M
else 4J 51i*`
break; A1t~&?
} pvQK6r
} >g"M.gW
catch(IOException e){e.printStackTrace ();} ^8l3j4
catch(Exception e){e.printStackTrace ();} 3?Eoj95w!
X8SRQO^
\pD=Lv9
Utility.log(nFileLength); V52C,]qQH
l8AEEG8>
hk!,
return nFileLength; QT= ,En
} sqpOS!]
hB}h-i(u
]baaOD$Z
//保存下载信息（文件指针位置） ]F*a PV
private void write_nPos() m_Ac/ctf
{ Ao,!z
try{ O][Nl^dl
output = new DataOutputStream(new FileOutputStream(tmpFile)); [+MX$y
output.writeInt(nStartPos.length); Xz.Y-5)
for(int i=0;i<nStartPos.length;i++) $K_YC~
{ 2 ssj(Qo
// output.writeLong(nPos); fxoi<!|iGY
output.writeLong(fileSplitterFetch.nStartPos); Ag4Ga?&8ec
output.writeLong(fileSplitterFetch.nEndPos); YyJ{
} Z'*Z@u3
output.close(); 87pXv6'FQ
} hKZ`DB4
catch(IOException e){e.printStackTrace ();} ,WB_C\.#XN
catch(Exception e){e.printStackTrace ();} Z-h7
} )x8;.@U
Ds%&Mi
1^f.5@tV
//读取保存的下载信息（文件指针位置） =1 BNCKT<
private void read_nPos() ~l*?D7[o
{ hUT^V(
try{ v]{uxlh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o%WjJ~!zL
int nCount = input.readInt(); w0j/\XN2s
nStartPos = new long[nCount]; yB4H3Q )
nEndPos = new long[nCount]; 8lWH=kA\
for(int i=0;i<nStartPos.length;i++) {`H<=h__
{ M9s43XL(&
nStartPos = input.readLong(); m&`(pf4A
nEndPos = input.readLong(); Gkv~e?Kc~^
} \SiHrr5
input.close(); puS&S *
} Q1nDl
catch(IOException e){e.printStackTrace ();} hP1 l v7P
catch(Exception e){e.printStackTrace ();} WfDX"rA
} a\{1UD
]KXMGH_
K4k~r!&OU
private void processErrorCode(int nErrorCode) M6jp1:ZH2q
{ ![@T iM
System.err.println("Error Code : " + nErrorCode); )v52y8G-p
} 4j@i%
5K ,#4EOV
IObx^N_K
//停止文件下载 _}e7L7B7g
public void siteStop() %/y`<lJz(
{ Z6^QB@moj
bStop = true; @1qdd~B}
for(int i=0;i<nStartPos.length;i++) n|x$vgb
fileSplitterFetch.splitterStop(); 1@%B?
2<'`^AO@
e`Co,>W/
} ?jri!]ux#
} -*|:v67C&
//负责部分文件的抓取 /BMtcCPG!
**FileSplitterFetch.java ms}f>f=
*/ `s`C{|wv
package NetFox; /}w#Jk4pD
y7JZKtsFA
WgA`kT
import java.io.*; ^Ue0mC7m
import java.net.*; bR`rT4.F
JAlU%n?R
izPh1YA
public class FileSplitterFetch extends Thread { w{3Q( =&
pd4cg?K
-]Q(~'a
String sURL; //File URL 6P~aW
long nStartPos; //File Snippet Start Position -=$% {
long nEndPos; //File Snippet End Position Z&FkLww
int nThreadID; //Thread's ID x" 'KW (
boolean bDownOver = false; //Downing is over K DYYB6|
boolean bStop = false; //Stop identical {)V?R
FileAccessI fileAccessI = null; //File Access interface >*dQqJI
kDzj%sm!
=n-z;/NL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WY+(]Wkao
{ LY-lTr@A^
this.sURL = sURL; }iilzE4oH#
this.nStartPos = nStart; "v(G7*2
this.nEndPos = nEnd; xfq]9<
nThreadID = id; F#(.v7Za
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ch@x]@-;A3
} >dpbCPJ9[
Ag0]U
yjEI/9_
public void run() Bx(yu'g|a
{ ! FNf>z+
while(nStartPos < nEndPos && !bStop) 5x8'K7/4.
{ YywEZ?X
],8;eq%W)
E: 9o;JU
try{ % f2<U;ff
URL url = new URL(sURL); ?ork^4 $s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cYGRy,'gH
httpConnection.setRequestProperty("User-Agent","NetFox"); 1~%o}+#-
String sProperty = "bytes="+nStartPos+"-"; ,e9CJ~a
httpConnection.setRequestProperty("RANGE",sProperty); zKLn!b#>
Utility.log(sProperty); NSw<t9Yi
XQ]`&w(
g b -Bxf
InputStream input = httpConnection.getInputStream(); ngP7'1I
//logResponseHead(httpConnection); 2~f6~\4GL+
NB EpM
$ye^uu;Z
byte[] b = new byte[1024]; xXF2"+
int nRead; W_^>MLq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ajW[eyX
{ jFtg.SD
nStartPos += fileAccessI.write(b,0,nRead); $#5klA
//if(nThreadID == 1) %drJ p6n%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 81Z4>F:
} Qi_&aU$>lM
bA9CO\Pp`
$^t<9"t
Utility.log("Thread " + nThreadID + " is over!"); ,Ij=b
bDownOver = true; bSQRLxF
//nPos = fileAccessI.write (b,0,nRead); )8;{nqoC
} j"5Pe
catch(Exception e){e.printStackTrace ();} xw?CMA
} (@ "=F6P
} v"rl5x
2G?$X?
1t+%Gv^sK
//打印回应的头信息 tJ"az=?
public void logResponseHead(HttpURLConnection con) Yi 6Nw+$
{ Rho5s@N7
for(int i=1;;i++) -Q#o)o
{ HOfF"QAR$
String header=con.getHeaderFieldKey(i); Q uB+vL
if(header!=null) yz?q(]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @rF/]UJ
Utility.log(header+" : "+con.getHeaderField(header)); 1!!\+ c2*
else RU6KIg{H
break; Ls]@icH0
} r*chL&7
} i^WIr h3a
lzEb5mg
W6vf=I@f
public void splitterStop() AM'gnP>
{ *8PN!^
bStop = true; +P|2m"UA
} vv &BhIf3
D}w<84qX
n12UBvc}%
} W2`.RF^
7F9;Su3.
`)$`-Pw*
/* nTs/Q V
**FileAccess.java 3YW=||;|Yg
*//文件访问(定位，写) p#bhz5&/
package NetFox; ryg4hHspl
import java.io.*; -ui<E?v
.]P2}w)x?
&'s^nn]
public class FileAccessI implements Serializable{ 8V-,Xig;`
ACb/ITu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s"i~6})K<$
RandomAccessFile oSavedFile; ,t1vb3
long nPos; (= 9wo
hT'=VN
M'q'$)e
public FileAccessI() throws IOException G+VD8]!K1
{ =h|wwQE
this("",0); rnO0-h-;
} +dw!:P&
=NZ[${7mq
D<t~e$H
public FileAccessI(String sName,long nPos) throws IOException |g<*Rk0
{ i?;R}%~
oSavedFile = new RandomAccessFile(sName,"rw"); {^J!<k,R\;
this.nPos = nPos; wz#A1F
oSavedFile.seek(nPos); z1vw'VT>
} 7d;pvhnH
'z5h3J
V@%
public synchronized int write(byte[] b,int nStart,int nLen) \gItZ}+c4}
{ E"#Xc@
int n = -1; 1CkdpYjsj
try{ mibpG9+d
oSavedFile.write(b,nStart,nLen); VYaSB?`/
n = nLen; ^ S
} X\\7$
catch(IOException e) Q`A6(y/s?
{ @*(4dt:V
e.printStackTrace (); "ZT.k5Z
} _yvLuj
|CIC$2u
f@@s1gdb
return n; blahi]{Y9
} #r<?v
R*9NR,C
wAFW*rO5o
} ]\Xc9N8w
Gf0,RH+
02\JzBU
/* m!O;>D
**SiteInfoBean.java !8R@@,_v
*/ }HRK?.Vj:
package NetFox; *5OCqU+g
BAV>o|-K
C!&y
public class SiteInfoBean { ,%W<O.
inAAgW#s}
c*;7yh&%
private String sSiteURL; //Site's URL I :)W*SK
private String sFilePath; //Saved File's Path \NK-L."[
private String sFileName; //Saved File's Name }$kQs!#
private int nSplitter; //Count of Splited Downloading File Qx)Jtb0`V
h2w}wsb0l
l&W;b6L
public SiteInfoBean() y3eHF^K+$
{//nSplitter的缺省值为5 >MG(qi
//default value of nSplitter is 5 2(M6(xH>
this("","","",5); #yW\5)
} o>?*X(+le
AIRr{Y
bMKL1+y(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QI}E4-s8
{ U# JIs
sSiteURL= sURL; ~AZWds(,N
sFilePath = sPath; nfdq y)
sFileName = sName; ` ;)ZGY\
this.nSplitter = nSpiltter; o.7{O,v
5$rSEVg9
h}L}[
} fuX'~$b.fA
EQ<RDhC@b
nSx]QREL!
public String getSSiteURL() Paj vb-f
{ r~7:daG*
return sSiteURL; =f1B,%7G+5
} hs+kr?Pg`
T vtm`Yk\
{9LWUCpsf
public void setSSiteURL(String value) Bs;|D
{ 0;.<~;@h
sSiteURL = value; JkQ\)^5v
} ;V5yXNQ
~1kXUWq3
k2 Q qZxm!
public String getSFilePath() v~|?3/{Q
{ (%_n!ip^
return sFilePath; f)Xr!7
} {ZsdLF#
0?0Jz
'CR)`G_'[
public void setSFilePath(String value) ve6w<3D@
{ Wu1{[a|
sFilePath = value; ]J7Qgp)i
} 9`Q<Yy"du
$s5a G)?7
^U[D4UM
public String getSFileName() :dI\z]Y(
{ MXD4|r(
return sFileName; @b#^ -
} k1 -~
t*XN_=E$f
FFKGd/:!
public void setSFileName(String value) \ I`p|&vG
{ wzCUZ1N9q
sFileName = value; sTRJ:fR
} je/!{(
O,@~L$a:YZ
I=DxRgt
public int getNSplitter() 7q=G&e7
{ K(}AX+rIg
return nSplitter; MrRaU x6z
} 1.<q3q
Zw1U@5}A
^P'{U26
public void setNSplitter(int nCount) 'x"08v$
{ !h[VUg_8
nSplitter = nCount; XFVV},V
} lj=l4 &.i
} *l&S-=]
5Por "&%
]b/S6oc6
/* m!tx(XsXU
**Utility.java Z;l`YK^-
*/ Ev"|FTI/
package NetFox; \55VqGyxu9
@%ip7Y]e
RoGwK*j0+
public class Utility { W,^W^:m-x
Gq<X4C#|
Z6p5*+
public Utility() T:]L/wCj
{ BQH}6ueZ
!TM*o+;
=3ioQZ^Vz
} _5 ^I.5Z3
'B5^P
//线程睡眠 ?S$i?\Qh
public static void sleep(int nSecond) l:#-d.z#
{ )rW&c-'
try{ :r#)z4d5
Thread.sleep(nSecond); azQD>
} ev1 W6B-a
catch(Exception e) 8lF\v/vN
{ 1NQbl+w#I
e.printStackTrace (); lKWPTCU
} ~S,p?I
} mrIh0B:`
7\]E~/g
//日志 7/7Z`
public static void log(String sMsg) sg'pO*_&
{ /S5|wNu
System.err.println(sMsg); (+uj1z^
} tGA :[SP
[r+ZE7$2b"
hpTDxh'?$C
public static void log(int sMsg) uiq^|5Z
{ qyC=(v
System.err.println(sMsg); 'r1LSht'
} )^||\G
} zDhB{3-Q1{
<fCKUc
g~V+4+
/* qd3Q}Lk
**TestMethod.java No]~jnqDM
*/ o<IAeH {+
package NetFox; /~*_x=p:
Lip4)Y [
,p(<+6QZ
public class TestMethod { 76hOB@
3rLTF\
8k q5ud
public TestMethod() !Z VU,b>
{ ///xx/weblogic60b2_win.exe _iNq"8>2
try{ ~{sG| ;/!*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !EUan
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bqma\1cgb
SiteFileFetch fileFetch = new SiteFileFetch(bean); W>-Et7&2
fileFetch.start(); A_Frk'{qhB
} 4DZ-bt'
catch(Exception e){e.printStackTrace ();} "-@[R
4_Dp+^JF
`u>4\sv
} {*{Ox[Nh{
Eu"_MgD
'y8]_K*
public static void main(String[] args) U9b?i$
{ ~4"qV_M
new TestMethod(); WAdCF-S
} 4pw6bK,s2\
} q6YXM
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