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)); *B`wQhB%
} [3rvRJ.
for(int i=0;i<nEndPos.length-1;i++) V5RfxWtm:
{ ,y?0Iwf
nEndPos = nStartPos[i+1]; Vo"\nj
} W04-D
nEndPos[nEndPos.length-1] = nFileLength; bY;ah;<
} oO>mGl36H
} `hL16S
5>JrTO5
dHzo_VV
//启动子线程 >t O(S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BfIGw
for(int i=0;i<nStartPos.length;i++) -2mm 5E~N
{ QE$sXP7&u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y%\kgWV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HkEfBQmh
nStartPos,nEndPos,i); Qg9 N?e{z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }0|,*BkI m
fileSplitterFetch.start(); KyNv)=x4c
} \ M8;CN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }ruBbeQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x2[A(O=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FU~ Ip
nEndPos = " + nFileLength); izow=}
// fileSplitterFetch[nPos.length-1].start(); +^!&-g@(
=x9zy]
e&E""ye
//等待子线程结束 n_hV;
//int count = 0; &aaXw?/zr
//是否结束while循环 ](@Tbm8
boolean breakWhile = false; S=ebht=
q3e%L
!,PG!Gnl
while(!bStop) s7iguFQ
{ 8AVM(d@
write_nPos(); *)ZDN~z7o
Utility.sleep(500); sV'(y>PP%
breakWhile = true; X4lz?Y:*
z'JtH^^Z
kA{[k
for(int i=0;i<nStartPos.length;i++) Uo<d]4p $
{ +glT5sOk
if(!fileSplitterFetch.bDownOver) [&y{z-D>
{ o4,W!^n2
breakWhile = false; kf>oZ*/
break; a8FC#kfq
} xf?*fm?m
} Y'`w.+9
if(breakWhile) )VID ;l;4
break; B_anO{3$4
&%}6&PWi
iZB?5|*
//count++; ogH{
//if(count>4) Lk6UT)C
// siteStop(); 1j "/}0fx
} I1S*=^Z_U
DDyeNuK
V.6h6B!vB
System.err.println("文件下载结束！"); p@y?xZS
} %:sQ[^0
catch(Exception e){e.printStackTrace ();} oEd+
} ?`,<l#sj
>fPa>[_1
9"KEHf!
//获得文件长度 +ZEj(fd9
public long getFileSize() <T+)~&g$
{ YN#i^(
int nFileLength = -1; De@GNN"-
try{ ,8nu%zcVn
URL url = new URL(siteInfoBean.getSSiteURL()); |?hNl2m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u;GS[E4
httpConnection.setRequestProperty("User-Agent","NetFox"); i<l_z&
K2<"O qp_W
7,ysixY
int responseCode=httpConnection.getResponseCode(); 9^,MC&eb
if(responseCode>=400) V)72]p
{ j BS$xW
processErrorCode(responseCode); Q\z6/1:9Z
return -2; //-2 represent access is error fwK5p?Xhm
} ~oy=2Q<Z
D |kdk;Xv
EaaQC]/OX5
String sHeader; 85+'9#~!
_SC{nZ[
)HQ':ZE$
for(int i=1;;i++) L\)ssOuh
{ )-%3;e<w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9&}$C]`
//Utility.log(in.readLine()); U,Ya^2h%
sHeader=httpConnection.getHeaderFieldKey(i); (pN:ETB
if(sHeader!=null) O%L]*vIr
{ j\iE3:94$
if(sHeader.equals("Content-Length")) bfcQ(m5
{ +sq'\Tbp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >7i&(6L
break; ul$k xc=N
} e`9d&"
} +e}v)N
else 7yM=$"'d
break; ~(OG3`W!
} {Z0(V"Q
} #d2XVpO[0
catch(IOException e){e.printStackTrace ();} Hd]o?q\
catch(Exception e){e.printStackTrace ();} .\XFhOsa
^3"~ T
/k8Lu+OJ
Utility.log(nFileLength); .}!"J`{W
g<pr(7jO
yNCd} 4Ym5
return nFileLength; [qbZp1s|(
} 4&%0%
,Ta k',
B;x5os
//保存下载信息（文件指针位置） ybNo`:8A;
private void write_nPos() Yuo:hF\DH
{ E><$sN6
try{ {\zTE1X9
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3/_rbPr
output.writeInt(nStartPos.length); pGz 5!d
for(int i=0;i<nStartPos.length;i++) K!W7a~ @
{ czNi)4x
// output.writeLong(nPos); \#Md3!MG
output.writeLong(fileSplitterFetch.nStartPos); 2%4u/
output.writeLong(fileSplitterFetch.nEndPos); E2dl}S zp
} 6S K;1Bp-{
output.close(); b9nTg
} 1eHU!{<fqm
catch(IOException e){e.printStackTrace ();} Zp8\n:
catch(Exception e){e.printStackTrace ();} by07l5
} uCkXzb9_z
e}lF#$
tVfZ~qJ
//读取保存的下载信息（文件指针位置） ) uM*`%
private void read_nPos() 6Qtyv
{ jW]Q-
try{ O-P'Ff"}t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bu0i#
int nCount = input.readInt(); atr0hmQ
nStartPos = new long[nCount]; M%&1j >d
nEndPos = new long[nCount]; +;r1AR1)x
for(int i=0;i<nStartPos.length;i++) U]/iPG&_
{ "x1?T+j4
nStartPos = input.readLong(); Me;XG?`
nEndPos = input.readLong(); /q1k)4?E
} YV%y KD
input.close(); ~mBY_[_s=
} g[G+s4Nv
catch(IOException e){e.printStackTrace ();} n_~u!Ky_P
catch(Exception e){e.printStackTrace ();} "w7{,HP
} 5Z;iK(>IX
v']Tusmg
4,g_$)
private void processErrorCode(int nErrorCode) RE._Ov>
{ }H#C<:A
System.err.println("Error Code : " + nErrorCode); _oz1'}=
} d1jg3{pwA
Z FIy
":v^Y 9
//停止文件下载 GJs{t1 E
public void siteStop() ]S0=&x@,
{ z}BuR*WSY{
bStop = true; K<wg-JgA
for(int i=0;i<nStartPos.length;i++) &/m0N\n?
fileSplitterFetch.splitterStop(); t,NE`LC
tJe5`L
-HwqR Ys
} -%fc)y&$
} +MR]h [
//负责部分文件的抓取 xig4H7V
**FileSplitterFetch.java q$7w?(Lk
*/ V36u%zdX5n
package NetFox; [_T6
Ly46S
>O]u4G!
import java.io.*; !w1acmo<_
import java.net.*; >//yvkZ9,
M{z&h>
&3Y"Zd!
public class FileSplitterFetch extends Thread { _xsHU`(J#
&?@gCVNO,
4V<.:.k
String sURL; //File URL 9y'To JZ6
long nStartPos; //File Snippet Start Position _|r/*(hh
long nEndPos; //File Snippet End Position .-4]FGg3
int nThreadID; //Thread's ID +\)a p
boolean bDownOver = false; //Downing is over 3:"w"0[K3
boolean bStop = false; //Stop identical ~Y3X*
FileAccessI fileAccessI = null; //File Access interface i.Z iLDs\7
20?@t.aMp
pi;'!d[l%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =:;K nS
{ 0I['UL^!F
this.sURL = sURL; X<mlaXwrA
this.nStartPos = nStart; 8KMo!p\i
this.nEndPos = nEnd; t+Au6/Dx?
nThreadID = id; |*n B2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,Vfjt=6]}
} )];Bo.QA
*"Uf|
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public void run() $(+#$F<eo+
{ 14z ?X%
while(nStartPos < nEndPos && !bStop) yV?qX\~*
{ 2uLBk<m5c
O b'Br
w9TE E,t;5
try{ Znd ,FqHk
URL url = new URL(sURL); rt'pc\|O&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %WlTx&jSgE
httpConnection.setRequestProperty("User-Agent","NetFox"); +=K =B
String sProperty = "bytes="+nStartPos+"-"; \-8S"
httpConnection.setRequestProperty("RANGE",sProperty); _o7t| pl~
Utility.log(sProperty); zEk/15
,{X}C
qT~a`ou:
InputStream input = httpConnection.getInputStream(); \wF-[']N
//logResponseHead(httpConnection); W5,&*mo
qNi`OVh&
MFQyB+Z
byte[] b = new byte[1024]; IxaF*4JG
int nRead; u~7fK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E<sd\~~A:
{ JA~q}C7A7o
nStartPos += fileAccessI.write(b,0,nRead); Lu CiO
//if(nThreadID == 1) X^Fc^U8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?&?5x%|.<
} {"c`k4R
JFFluL=-
>Og|*g
Utility.log("Thread " + nThreadID + " is over!"); nzU;Bi^m
bDownOver = true; xauMF~*
//nPos = fileAccessI.write (b,0,nRead); =SD^Jl{H
} ;zT3Fv\
catch(Exception e){e.printStackTrace ();} NG_7jZzXA9
} jss.j~8
} 3JEg3|M(
JKV&c=I
`BVXF#sb
//打印回应的头信息 K[yP{01
public void logResponseHead(HttpURLConnection con) 0.)q5B`
{ )H(i)$I
for(int i=1;;i++) iDWM-Ytx
{ -9Dr;2\
String header=con.getHeaderFieldKey(i); :!Nx'F9a
if(header!=null) 6aLRnH"Ud
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^?NLA&v<
Utility.log(header+" : "+con.getHeaderField(header)); Zc'^iDAY
else ,b4oV
break; uS5G(}[
} }N&?8s=
} ?|~KF:,#}
z69u@
cn: L]%<
public void splitterStop() 60 %VG
{ [*M':
bStop = true; QBh*x/J
} _F8THYg (
jZD)c_'U
/DjsnU~3
} aWPf3Q
bgxk:$E
i+F*vTM2,
/* /24}>oAH
**FileAccess.java >#)%/Ti}DU
*//文件访问(定位，写) EJ(36h
package NetFox; T%Bz>K
import java.io.*; .yDGwLry
/b\c<'3NY
NcBz("
public class FileAccessI implements Serializable{ et"Pb_-U
bB>.dC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xS>vmnW
RandomAccessFile oSavedFile; tW a'[2L
long nPos; !nq`PyMR
#m17cDL
{Kf5a m
public FileAccessI() throws IOException A{e>7Z72
{ w3z'ZCcr;"
this("",0); Ot)S\s>
} ik#Wlz`4
`5e{ec c7
3-&~jm~"
public FileAccessI(String sName,long nPos) throws IOException p8 Ao{
{ g)R2V
oSavedFile = new RandomAccessFile(sName,"rw"); c/igw+L()
this.nPos = nPos; =Z{jc
oSavedFile.seek(nPos); R$+p4@?S
} }LeS3\+UHl
:t<S
I&m' a
public synchronized int write(byte[] b,int nStart,int nLen) o2'Wu:Y"
{ 8N+T=c
int n = -1; >cLh$;l
try{ %`QgG
oSavedFile.write(b,nStart,nLen); z1]nC]2
n = nLen; ;rF[y7\
} r<4j;"lQK
catch(IOException e) Oet+$ b
{ PXqG;o*Q*?
e.printStackTrace (); jFJ}sX9]
} <_ENC>NP
shw"TF>?zG
N.H<'Q8&
return n; /&<V5?1|
} !/!ga)Y
_6V1oe2
iEZ+Znon
} CJER&"em7
a+cDH
gb|;]mk*"
/* IxS%V31
**SiteInfoBean.java iPCCTs
*/ ,wM4X']HR
package NetFox; ~\AF\n%
kiyc^s
Ix}6%2\
public class SiteInfoBean { /Q3\6DCl
0Sz[u\w
ZOMYo]
private String sSiteURL; //Site's URL NPrLM5
private String sFilePath; //Saved File's Path <e?Eva%t`
private String sFileName; //Saved File's Name 8Y.9%@
private int nSplitter; //Count of Splited Downloading File 9^ZtbmUf
SJ<v< B
atF#0*e>
public SiteInfoBean() ~D>pu%F
{//nSplitter的缺省值为5 KX]!yA
//default value of nSplitter is 5 g&y^r/
this("","","",5); %T\hL\L?
} 8*@{}O##
as|w} $
PCHspe9!y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )Z:D}r8[
{ `:;q4zij;
sSiteURL= sURL; E_aBDiyDf
sFilePath = sPath; Y*PfU+y~
sFileName = sName; g_`a_0v
this.nSplitter = nSpiltter; P!E2.K,
5K2K'ZkI
3V?x&qlP>
} .1jiANY
|5tZ*$nGa
~bxev/$d
public String getSSiteURL() TKv!wKI
{ xsn=Ji2 F
return sSiteURL; UUlz3"`
} eF22 ~P
.= ?*Wp
UJSIbb5
public void setSSiteURL(String value) m|B=&#
{ #$-E5R;x
sSiteURL = value; - ~|Gwr"
} xBA"w:<
#aU!f"SS
*>KBDFI
public String getSFilePath() 5C9b*]-#
{ e5>'H!)
return sFilePath; V7Cnu:0_
} (+epRC
7!pKlmQ
ZQ_6I}i")
public void setSFilePath(String value) ~}}<+JEEO
{ o~IAZU39
sFilePath = value; ~qrSHn}+PU
} ]|.ked
^0}ma*gi~
)ZpI%M?)
public String getSFileName() tLTavE[@
{ &Y=0 0
return sFileName; 14B',]`
} o+A1-&qhN
?gl&q+mv
w,LmAWZ4Y
public void setSFileName(String value) {:K_=IRZ
{ fUkqhqe
sFileName = value; 0X5cn 0L^
} <.QaOLD
7;fC%Fq
eZa*WI=
public int getNSplitter() 3- Kgz
{ bGH#s {'5
return nSplitter; j)mU`b_
} A~bSB n: '
_|#abLh%
B2ln8NF#Q
public void setNSplitter(int nCount) )}`z<)3jP
{ FOsd{Fw
nSplitter = nCount; I?3b}#&V9
} T,pr&1]Lw
} pT]hPuC
G+8)a$?v
E+@Q u "W
/* mvEhP{w
**Utility.java j2MA['{
*/ O8@65URKx
package NetFox; 0Idek
]`&_!T
bE !SW2:M
public class Utility { q!z"YpYB
@|anu&Hm
Y,)(Q
public Utility() Xfq`k/ W
{ lmzHE8MUNu
1_]X
\%a0Lp{ I
} 89FAh6uE
L/tpT?$fi
//线程睡眠 ?$f.[;mh
public static void sleep(int nSecond) 4H-eFs%5
{ yxt"vm;
try{ L@S\ rImw
Thread.sleep(nSecond); =6[.||9
} u?Ffqt9'
catch(Exception e) ?s^qWA
{ )j36Y =r3
e.printStackTrace (); ,<rC,4-F<
} .`OU\LA
} F}_b7|^
;'n%\*+fHH
//日志 =GX5T(P8k
public static void log(String sMsg) U6M~N0)Yr
{ VhUWws3E
System.err.println(sMsg); m^3x%ENZ
} \)~d,M}kK
el9P@r0
gZ,h95'
public static void log(int sMsg) odhS0+d^
{ Fc1!i8vv
System.err.println(sMsg); F/s n"2
} w \b+OW
} wXQxZuk[
YhN<vZ}U!~
Z=a%)Ki?Ag
/* 8_('[89m
**TestMethod.java t eY@)F
*/ {v|!];i
package NetFox; .Fo#Dmq3
"JB4Uaa
TJ"-cWpO1
public class TestMethod { xnZnbgO+
)zr*Ecz
BiYxI{VFD
public TestMethod() n~I-mR)"
{ ///xx/weblogic60b2_win.exe Z}+}X|
try{ z\]Z/Bz:6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WO qDW~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3a?-UT!
SiteFileFetch fileFetch = new SiteFileFetch(bean); QHR,p/p
fileFetch.start(); d0:LJ'<Q
} ^K?-+
catch(Exception e){e.printStackTrace ();} d?fS#Ryb
iW` tr
vE:*{G;Y
} keAoJeG,J
EQm{qc;
` 2W^Ui,4
public static void main(String[] args) e|]e\Or>
{ XGl2rX&
new TestMethod(); nI*.(+h
} <fUo@]Lv
} S^rf^%
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