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)); Uw2,o|=O
} #K:-Bys5v
for(int i=0;i<nEndPos.length-1;i++) $S6HZG:N
{ }XGMa?WR
nEndPos = nStartPos[i+1]; Z{,GZT
} 3wN?|N
nEndPos[nEndPos.length-1] = nFileLength; 0|fb< "
} "wnpiB}
} ;t;Y.*&=S
?fbgU
@pF fpHq?>
//启动子线程 5|<yfk8*J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eKZ@FEZ
for(int i=0;i<nStartPos.length;i++) C%}]"0Q1
{ &dhcKO<4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %YcxC0S[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Snc;p
nStartPos,nEndPos,i); T3USNc51
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b 0LGH. z4
fileSplitterFetch.start(); DU5:+" u3
} :]CzN^k(1c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [%j?.N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?a'6EAErC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >63)z I
nEndPos = " + nFileLength); <*s"e)XeqF
// fileSplitterFetch[nPos.length-1].start(); ^[{`q9A#d
j[J5y#
YG0PxZmi
//等待子线程结束 C5O5S:|'
//int count = 0; w5F4"nl#O}
//是否结束while循环 ?z2jk
boolean breakWhile = false; Tub1Sv>J
tigT@!`$Y
$&cz$jyY
while(!bStop) D(y+1^>
{ S~KS9E~\
write_nPos(); NH7`5mF$
Utility.sleep(500); 2\^G['9
breakWhile = true; $4Z+F#mx
QBy{|sQ`
bGbqfO`
for(int i=0;i<nStartPos.length;i++) 8zhBA9Y#~
{ 9n1ZVP.ag
if(!fileSplitterFetch.bDownOver) s}6+8fE"
{ ;{|X,;s
breakWhile = false; '.?^uM
break; yn SBVb!)
} *)u?~r(F
} Vclr)}5
if(breakWhile) EXuLSzQwv
break; a:85L!~:l
!; IJ
qu_)`wB
//count++; .*BA 1sjE
//if(count>4) ?w-1:NWjt
// siteStop(); }91*4@B7
} v?L
m6^ 5S
Q]@c&*_|
System.err.println("文件下载结束！"); L>dkrr)e
} -."kq.m*
catch(Exception e){e.printStackTrace ();} _a](V6
} I,b9t\(6
2-~|Z=eGW
Z7fg 25
//获得文件长度 T-'~?[v
public long getFileSize() F@Q^?WV
{ w/W7N
int nFileLength = -1; En(7(qP6}
try{ #uSK#>H_!
URL url = new URL(siteInfoBean.getSSiteURL()); 8'A72*dhX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LXj5R99S
httpConnection.setRequestProperty("User-Agent","NetFox"); q*,Q5
UUeB;'E+
8TE>IPjm
int responseCode=httpConnection.getResponseCode(); U&UKUACn"
if(responseCode>=400) "xe=N
{ U3E&n1AA
processErrorCode(responseCode); F30 ]
return -2; //-2 represent access is error Ha%F"V*
} 8Hi!kc;f6>
sYqgXE.
n2{SV
String sHeader; 7G<t"'
Iy';x
*/z??fI27
for(int i=1;;i++) ; Y"N6%
{ nPN?kO=]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6?qDdVR~]
//Utility.log(in.readLine()); bl;zR
sHeader=httpConnection.getHeaderFieldKey(i); O/Rhf[7v*
if(sHeader!=null) gd7^3q[$h
{ A(8n
if(sHeader.equals("Content-Length")) c)}2K0
{ w8Vw1wW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !2tW$BP^
break; ,+`HQdq
} 2&Jdf
} 4-R^/A0
else Wht(O~F
break; J~#$J&iKh
} n6MM5h/#r
} QAPu<rdJP
catch(IOException e){e.printStackTrace ();} w%y\dIeI'
catch(Exception e){e.printStackTrace ();} !ABiy6d
rJJ[X4$
vUA0FoOp
Utility.log(nFileLength); Sv'y e
l"(6]Z 4
e`K)_>^n#
return nFileLength; Zg~nlO2
} ]m4OIst
1LnyWZ
dRi5hC$
//保存下载信息（文件指针位置） B@y(.
private void write_nPos() <7_KeOLJ
{ 2xwlKmI N
try{ e@#kRklV&
output = new DataOutputStream(new FileOutputStream(tmpFile)); %JZZ%xc
output.writeInt(nStartPos.length); L<V3KS2y
for(int i=0;i<nStartPos.length;i++) "LhvzM-<8
{ "O[j!fG8,
// output.writeLong(nPos); N587(wZ
output.writeLong(fileSplitterFetch.nStartPos); o>Er_r
output.writeLong(fileSplitterFetch.nEndPos); 6w[}&pX"z
} j*v40mXl`2
output.close(); ? "/ fPV-
} m#vL*]c}
catch(IOException e){e.printStackTrace ();} w Y
catch(Exception e){e.printStackTrace ();} SqA J-_~
} A{eLl
+rXF{@ l
E Y<8B3y
//读取保存的下载信息（文件指针位置） sP@X g;]
private void read_nPos() b5G}3)'w
{ 6K`c/)
try{ `d]IX^;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cO2& VC
int nCount = input.readInt(); !4"^`ors$
nStartPos = new long[nCount]; U69u'G:
nEndPos = new long[nCount]; fBn"kr;
for(int i=0;i<nStartPos.length;i++) 4Y> Yi*n
{ (-77[+2
nStartPos = input.readLong(); Ny- [9S-<
nEndPos = input.readLong(); $~0Q@):
} *l+OlQI0+
input.close(); ?>c=}I#Ui-
} >LC<O.
catch(IOException e){e.printStackTrace ();} xo}b= v
catch(Exception e){e.printStackTrace ();} D]a:@x`+Bz
} wxg^Bq)D*R
dy__e^qi
rl#vE's6.e
private void processErrorCode(int nErrorCode) / $ :j
{ "@A![iP
System.err.println("Error Code : " + nErrorCode); 0MMEo~dih
} s=6}%%q6
B(?Yw>Xd[
=]`lN-rYw
//停止文件下载 u]-_<YZ'B
public void siteStop() 1n5(S<T
{ @`opDu!
bStop = true; :2 >hoAJJ
for(int i=0;i<nStartPos.length;i++) 0Sq][W=
fileSplitterFetch.splitterStop(); '>$EOg"
X,aYK;q%z
`afIYXP
} U[L9*=P;
} ).` S/F
//负责部分文件的抓取 D\w h;r
**FileSplitterFetch.java {rfF'@[
*/ DS-0gVYeDW
package NetFox; ?[<Tx-L
j"^+oxH
znJhP}(
import java.io.*; XqRJr%JH
import java.net.*; @E( 7V(m/
HoV^Y6
d)cOhZy
public class FileSplitterFetch extends Thread { '{I_\~*
=deMd`=J
fDE%R={!n5
String sURL; //File URL C51bc6V
long nStartPos; //File Snippet Start Position CQ`=V2:"ON
long nEndPos; //File Snippet End Position LE5.b]tv2
int nThreadID; //Thread's ID ~R$~&x(b
boolean bDownOver = false; //Downing is over 4n#ov=)-~
boolean bStop = false; //Stop identical iv`O/T
FileAccessI fileAccessI = null; //File Access interface }+o:j'jB
MV_Srz
~DRmON5 M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "mL++>ZSQ
{ c4&'D;=
this.sURL = sURL; 73{'kK
this.nStartPos = nStart; Q9}dHIe1E
this.nEndPos = nEnd; DRqZ,[!+
nThreadID = id; o1&:ry
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -<jL~][S
} Fhv/[j^X
g %K>
[7(-T?_
public void run() O}9KJU
{ }$MN|s
while(nStartPos < nEndPos && !bStop) r`)L~/
{ M8H5K
08X_}97#WF
f\'{3I29
try{ yC 77c=
URL url = new URL(sURL); '$4O!YI9@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !fBF|*/
httpConnection.setRequestProperty("User-Agent","NetFox"); pa}*E
String sProperty = "bytes="+nStartPos+"-"; Z_\C*^
httpConnection.setRequestProperty("RANGE",sProperty); ?JL7=o X
Utility.log(sProperty); J=.`wZQkS
$^u}a
go+Q~NV
InputStream input = httpConnection.getInputStream(); UobyK3.%
//logResponseHead(httpConnection); H|cNH=
85EQ5yY
#%J5\+ua
byte[] b = new byte[1024]; $+.l*]
int nRead; l3N I$Zu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7t,t`
{ dU\%Cq-G)
nStartPos += fileAccessI.write(b,0,nRead); *[=bR>
//if(nThreadID == 1) "V{yi!D{<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G:x*BH+
} e><5Pr)
7~#:>OjW
E\gim<]
Utility.log("Thread " + nThreadID + " is over!"); 7'NwJ,$6\
bDownOver = true; VqL.iZ-
//nPos = fileAccessI.write (b,0,nRead); +[SgO}sF
} 2pdvWWh3l
catch(Exception e){e.printStackTrace ();} pP(XIC
} iC iZJ"
} JdZ+Hp3.
JCAq8=zM
<~ JO s2
//打印回应的头信息 3\T2?w9u(
public void logResponseHead(HttpURLConnection con) O;7)Hjwt
{ f|u#2!7
for(int i=1;;i++) qj cp65^
{ ]%Zz \Q
String header=con.getHeaderFieldKey(i); NEa>\K<\
if(header!=null) r>bJ%M}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N'xSG`,Mg
Utility.log(header+" : "+con.getHeaderField(header)); *T0q|P~o%
else k6=nO?$
break; `9k0Gd
} 0Z{j>=$
} npRSEv
r>GZ58i
#+$Q+Z|6k
public void splitterStop() v&Kqq!DE
{ !mXxAo
bStop = true; T{wuj[Q#:
} u&wiGwF[
j5@:a
K'#E3={tt
} +H$!a
=IAsH85Q
0ZQ'_g|%
/* ccd8O{G.M
**FileAccess.java 1:Si,d,wh
*//文件访问(定位，写) l }XU59
package NetFox; Z$J#|
import java.io.*; dL|+d:v
jY_T/233d
u.rY#cS,-R
public class FileAccessI implements Serializable{ wf1lyS
&~CY]PN.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ] }f9JNf$
RandomAccessFile oSavedFile; Pz$R(TV
long nPos; q\\gpCgp
vFEQ7qI
86 W0rS[5
public FileAccessI() throws IOException Ecs,$\
{ %v2R.?F8
this("",0); H(Eh c
} [@4rjGwB
HYmn:?H
<V>dM4Mkr
public FileAccessI(String sName,long nPos) throws IOException UwC=1g U
{ _#vrb;.+
oSavedFile = new RandomAccessFile(sName,"rw"); y!]CJigpZ
this.nPos = nPos; ExRe:^yU\
oSavedFile.seek(nPos); ?k(\ApVHj
} ws^4?O
sUE?v9
&>H!}"Yk
public synchronized int write(byte[] b,int nStart,int nLen) !Ra*)b"
{ =~p>`nV
int n = -1; ]vuwkn+)
try{ _ 84ut
oSavedFile.write(b,nStart,nLen); XV^1tX>f{
n = nLen; Hty0qr3
} A/`%/0e
catch(IOException e) XkyKBg-
{ IUtx!.]4
e.printStackTrace (); "--t e
} >3&O::]3
d|4}obCt
`O'`eY1f
return n; Ao/ jt<
} |g*XK6
;qBu4'C)T
T9s2bC.z55
} @gG<le6
ES40?o*]x
N<DGw?Rl
/* \(%Y%?dy
**SiteInfoBean.java '? jlH0;
*/ jMpD+Mb
package NetFox; 0>zbCubPH
VsA'de!V4[
]n-:Yv5 W
public class SiteInfoBean { tY <Z'xA?
xCtmXo
-1J[n0O.
private String sSiteURL; //Site's URL ]KJj6xn
private String sFilePath; //Saved File's Path R i^[i}
private String sFileName; //Saved File's Name tr7<]Hm:
private int nSplitter; //Count of Splited Downloading File _2N$LLbg
D1&A,2wO
<\;#jF%V
public SiteInfoBean() KgR<E
{//nSplitter的缺省值为5 8n>9;D5n
//default value of nSplitter is 5 im @h -A]0
this("","","",5); LQjsOo
} 8.[SU
'e6WDC1Am(
GQ |Mr{.;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t#2(j1
{ P 3'O/!
sSiteURL= sURL; x.q+uU$^
sFilePath = sPath; R+CM`4CD
sFileName = sName; O|w J)
this.nSplitter = nSpiltter; KIWe@e
%dY<=x#b
xNbPsoK
} yiO.z
F8apH{&t
50={%R
public String getSSiteURL() |DsnNk0c
{ xt*u4%
return sSiteURL; sM9+dh
} ^`G}gWBx}w
l]5w$dded~
O?|gp<=d
public void setSSiteURL(String value) f!JS= N?3
{ Qubp9C#r
sSiteURL = value; ^#sU*trr
} Dtj&W<NXo
Jkek-m
pxa(
public String getSFilePath() 4]E3cAJ
{ qT^I?g"!
return sFilePath; uS^Ipxe\
} G["c\Xux
w`5xrqt@
Ih"XV
public void setSFilePath(String value) cCxBzkH6
{ p3^m9J
sFilePath = value; ynrT a..
} ^U!0-y
}I>tO9M
LEtG|3Dx
public String getSFileName() k`N^Vdr
{ 5s]. @C8
return sFileName; 9th,VnD0
} r >nG@A
gN"7be&J
.p(T^ m2A*
public void setSFileName(String value) 9B9(8PVG
{ 5^x1cUB]
sFileName = value; Z+=@<i''
} 5@BBoeG
{lc\,F*$
hzvd t
public int getNSplitter() &oX>*6L
{ ^cuc.g)c$?
return nSplitter; d}4Y(
} ZEx}$<)_
\7'+h5a
0ik7v<:
public void setNSplitter(int nCount) 9_5ow
{ |/)${*a4n
nSplitter = nCount; :n-]>Q>5=k
} tw9f%p
} l~$+,U&XNe
IqoR7ajA
5wDg'X]>V
/* XD2v*l|Po
**Utility.java Kuu *&u
*/ AQwdw>I-FX
package NetFox; &*aIEa^
6g)GY"49
,JQp'e
public class Utility { ]'=)2 .}
W}mn}gTQ
>: g3k
public Utility() R)m'lMi|
{ {fjdr
7](KV"%V
"9Q40w\
} =D<PVGo9
]Yn_}Bq
//线程睡眠 SR|`!
public static void sleep(int nSecond) bl&nhI)w
{ tu66'z
try{ *(T:,PY
Thread.sleep(nSecond); GVYkJ0,
} Yz+ZY
catch(Exception e) rr02pM0
{ !*B'?|a<\
e.printStackTrace (); M# %a(Y3K)
} NdD`Hn-
} z)r=+ -
E;R n`oxk
//日志 /~$WUAh
public static void log(String sMsg) I!Z_[M
{ lrIjJ V
System.err.println(sMsg); waj0"u^#
} =E#%'/ A;c
Eu@huN*/
Oagsoik
public static void log(int sMsg) c2'Lfgx4
{ &keR~~/
System.err.println(sMsg); :7]Sa`
} =*c7i]@}
} .7avpOfz
#PH~1`vl
\=ux atw
/* (G;lx
**TestMethod.java U`NjPZe5^
*/ '9 [vDG~
package NetFox; .ufTQ?Fe
(jRm[7H
?En O"T.
public class TestMethod { :fZ}o|t7
QLiu2U o
'O_3)x5
public TestMethod() !C3MFm{B
{ ///xx/weblogic60b2_win.exe |es?;s'
try{ PuA9X[=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `-J%pEIza
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zkuU5O
SiteFileFetch fileFetch = new SiteFileFetch(bean); eo?;`7
fileFetch.start(); o.!~8mD
} keX,d#
catch(Exception e){e.printStackTrace ();} 2j}\3Pi
yy i#Mo ,
pm 9"4z
} YA_c N5p/@
IID-k
v,-HU&/*B
public static void main(String[] args) RL@VSHXc
{ c|B.n]Z
new TestMethod(); !h23cj+V
} IYS)7`{]
} SwTL|+u
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