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)); +K$NAT
} [QczlwmO
for(int i=0;i<nEndPos.length-1;i++) *"{&FEV
{ x?yD=Mq_
nEndPos = nStartPos[i+1]; acW'$@y9?N
} G^Tk 20*
nEndPos[nEndPos.length-1] = nFileLength; C"w {\ &R
} Ru\_dr2yI}
} 1np^(['ih
U4,2br>
m7qqY
//启动子线程 }5 9U}@xC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lmCZ8 j(FF
for(int i=0;i<nStartPos.length;i++) NgZUnh3{
{ /Cr/RG:OX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b.yh8|&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0GXO&rCG
nStartPos,nEndPos,i); q6q1\YB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y)I8eU{Wl(
fileSplitterFetch.start(); KeBQH8A1N
} *nTU#U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8im@4A+n`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /VTM 9)u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y'M#z_.z
nEndPos = " + nFileLength); B]iP't\~
// fileSplitterFetch[nPos.length-1].start(); 0E/:|k
_|{aC1Y!V
!?FK We
//等待子线程结束 1s7^uA$}6
//int count = 0; 2k -+^}r
//是否结束while循环 C!x/ ^gw
boolean breakWhile = false; >'=MH2;
%{5n1w
HgRwiIt
while(!bStop) gn1(4 o
{ l=P'B @,
write_nPos(); eC`pnE
Utility.sleep(500); ljJ>;g+
breakWhile = true; z3?\:Yz
`NNf&y)y
6f%DpJ:$U
for(int i=0;i<nStartPos.length;i++) RMXzU
{ yJJ4~j){l
if(!fileSplitterFetch.bDownOver) EeQ5vqU
{ yJ2B3i@T4
breakWhile = false; JBX[bx52<r
break; dZ(|uC!?
} 4dh+
} Ca>&
if(breakWhile) )NW6?Pu"
break; ]<w:V`(
5\4g>5PD
=hH.zrI6e
//count++; 5z/Er".P
//if(count>4) )mN9(Ob!
// siteStop(); 2XSHZ|;
} e$/B_o7(
u\e\'\
zA+@FR?
System.err.println("文件下载结束！"); !]?$f=
} P\R27Jd
catch(Exception e){e.printStackTrace ();} tpf7_YP_!-
} +C{p%`<
A}VYb:u/
8HErE<_(
//获得文件长度 Qo0H
public long getFileSize() r0dDHj~F
{ lX!`zy{3k
int nFileLength = -1; 6j9)/HP
try{ c+' =hR[
URL url = new URL(siteInfoBean.getSSiteURL()); &*,:1=p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c|~6Ie
httpConnection.setRequestProperty("User-Agent","NetFox"); e 9$C#D>D
%Z]'!X
j2n,f7hl.
int responseCode=httpConnection.getResponseCode(); udqS'g&
if(responseCode>=400) Q=cQLf;/'
{ 'ktHPn ,K
processErrorCode(responseCode); C;B}3g&
return -2; //-2 represent access is error Xa9TS"
} d+L#t
(jWss V1
Cpl;vQ
String sHeader; ]`=X'fED
]Uc`J8p,
S01wwZ
for(int i=1;;i++) N=1JhjVk"
{ tykB.2f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5i So8*9}
//Utility.log(in.readLine()); (Ye>Cp+]
sHeader=httpConnection.getHeaderFieldKey(i); jx`QB')kX
if(sHeader!=null) 3K0tC=
{ `iShJz96
if(sHeader.equals("Content-Length")) JC;^--0(z
{ u' Qd,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xh+ia#K
break; hZ\+FOx;
} 8nNsrat
} C'mL&
else H}0dd"
break; u=+q$Q]
} c9Es%@]
} ,d,\-x-+/
catch(IOException e){e.printStackTrace ();} ]gb=
catch(Exception e){e.printStackTrace ();} B0UJq./`
HL{$ ^l#v
wdE?SDs
Utility.log(nFileLength); %'Xk)-+y
&~DTZgY
Z'v-F^
return nFileLength; T6#"8qz<
} 'W. Vr4
Z0,~V
d.<~&.-$
//保存下载信息（文件指针位置） k)(Biz398E
private void write_nPos() Y;J*4k]
{ ?:rx1}:F
try{ h rN%
output = new DataOutputStream(new FileOutputStream(tmpFile)); o@E/r.uK
output.writeInt(nStartPos.length); -7-['fX
for(int i=0;i<nStartPos.length;i++) )|#%Czd4
{ _sHK*&W{CT
// output.writeLong(nPos); dWRrG-'
output.writeLong(fileSplitterFetch.nStartPos); Zf*r2t1&P
output.writeLong(fileSplitterFetch.nEndPos); ZFh+x@
} %i{;r35M;9
output.close(); *e"a0
} cd@.zg'sYn
catch(IOException e){e.printStackTrace ();} 8%{q%+
catch(Exception e){e.printStackTrace ();} !UBO_X%dz
} V1=*z
dx_6X!=.J
Bo_ym36N
//读取保存的下载信息（文件指针位置） j0-McLc
private void read_nPos() {OMgd3%14
{ D #2yIec
try{ zri} h/{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /M0/-pV9
int nCount = input.readInt(); B\`Aojw"E?
nStartPos = new long[nCount]; 7hNb/O004
nEndPos = new long[nCount]; /L=(^k=a.;
for(int i=0;i<nStartPos.length;i++) " BTE
{ F 8yF
nStartPos = input.readLong(); %oykcf,#
nEndPos = input.readLong(); }E<^gAh}
} LwJ0
input.close(); ENh8kD l5
} Ps[$.h
catch(IOException e){e.printStackTrace ();} eH>#6R1-
catch(Exception e){e.printStackTrace ();} "AueLl)
} c$E)P$<j
*e.*=$
;]D(33)(
private void processErrorCode(int nErrorCode) H6kf K5,
{ D}mL7d1
System.err.println("Error Code : " + nErrorCode); &wH:aD
} QOFvsJ<s
H:&?ha,9
G&{HTYP
//停止文件下载 | FM }
public void siteStop() %B2XznZ:
{ P!g-X%ngo
bStop = true; X~T/qFS
for(int i=0;i<nStartPos.length;i++) C"<s/h
fileSplitterFetch.splitterStop(); TvhJVVQ+?
N0TeqOi4Y
Ibr%d2yS=
} 8Cf|*C+_'
} "l~Ci7& !a
//负责部分文件的抓取 3 pWM~(#>-
**FileSplitterFetch.java OmMX$YID
*/ #XIc "L)c
package NetFox; g$37;d3Tx
".2K9j7$
mNmUUj9z
import java.io.*; R'K/t|MC
import java.net.*; lP<I|O=z
Se^^E.Z,W
>wON\N0V_
public class FileSplitterFetch extends Thread { bi[7!VQf
<>&=n+i
I+?hG6NM
String sURL; //File URL rs8\)\z
long nStartPos; //File Snippet Start Position B&KL2&Z~Pq
long nEndPos; //File Snippet End Position {ShgJ;! Q
int nThreadID; //Thread's ID mB55PYA
boolean bDownOver = false; //Downing is over Un=a fX?j
boolean bStop = false; //Stop identical +Ghi}v
FileAccessI fileAccessI = null; //File Access interface 7!V@/S}7
d.F)9h]XHO
/I{R23o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E)p9eU[#
{ sa-9$},z4
this.sURL = sURL; }6m?d!m
this.nStartPos = nStart; m\0cE1fir
this.nEndPos = nEnd; mw$Y
nThreadID = id; .J.vC1 4gi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b[^{)$(
} x"B'zP
Utl t<
loOOmHhJ&
public void run() P_4DGW
{ Lubrn"128
while(nStartPos < nEndPos && !bStop) cnNOZ$)
{ v"lf-c
4iX-(ir,
je%M AgW`
try{ P~7.sM
URL url = new URL(sURL); H[&@}v,L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >IvBUM[Rt
httpConnection.setRequestProperty("User-Agent","NetFox"); 'imU`zeo
String sProperty = "bytes="+nStartPos+"-"; p]|LV)R n
httpConnection.setRequestProperty("RANGE",sProperty); *o?i:LE]
Utility.log(sProperty); Fz"ff4Bx [
f05d ;
#gZ|T M/h
InputStream input = httpConnection.getInputStream(); ~9M!)\~
//logResponseHead(httpConnection); ;IP~Tb]&
D!3{gV#
v548ysE)
byte[] b = new byte[1024]; 5G*II_j
int nRead; P'[<AZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m#@_8_ M
{ hl/itSl$
nStartPos += fileAccessI.write(b,0,nRead); a|qsQ'1,;
//if(nThreadID == 1) MK$Jj"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q? z>
} <4X?EYaTq
=:7$/T'Qg
Ob@Hng%v
Utility.log("Thread " + nThreadID + " is over!"); nB@UKX
bDownOver = true; @z,*K_AKr
//nPos = fileAccessI.write (b,0,nRead); KFhG(
} wyQb5n2`;~
catch(Exception e){e.printStackTrace ();} V'wi^gq
} K&`Awv
} ohZx03
x7ATI[b[
NPU^)B
//打印回应的头信息 S7sb7c'4 k
public void logResponseHead(HttpURLConnection con) \9m*(_Qf
{ ?Myh7
for(int i=1;;i++) O.\h'3C
{ 7sV/_3H+
String header=con.getHeaderFieldKey(i); 3oBC
if(header!=null) (F5ttQPh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -F`he=Ev9
Utility.log(header+" : "+con.getHeaderField(header)); MOZu.NmO
else otriif@+Z
break; zB)%lb
} s (PY/{8
} >;lKLGJrd>
\Ow,CUd
~<O,Vs_C/
public void splitterStop() 0D3OE.$0
{ tbur$00
bStop = true; {*xBm#
} ejcwg*i
3wt
(2txM"Dja
} PZOORjF8A
~"7J}[i5
fPQ|e"?
/* VXC4%
**FileAccess.java %$n02"@
*//文件访问(定位，写) \qq-smcM-
package NetFox; Q1V2pP+=@
import java.io.*; /~hbOs/ L
2VYvO=KA
h}6_ybmZ
public class FileAccessI implements Serializable{ [m#NfA:h,
xs1bxJ_R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kK?zVH-!
RandomAccessFile oSavedFile; Bw-s6MS
long nPos; V5s&hZZYa
dU+0dZdKO
[x_s/"Md;
public FileAccessI() throws IOException l9Pu&M?5
{ $9H[3OZPVv
this("",0); jT^!J+?6K+
} 0xP:9rm
fN[n>%)VO<
{j@+h%sF>+
public FileAccessI(String sName,long nPos) throws IOException -Enbcz(B
{ I~RcOiL)
oSavedFile = new RandomAccessFile(sName,"rw"); Phlk1*1n
this.nPos = nPos; \(u@F<s-
oSavedFile.seek(nPos); (j N]OE^
} Wem?{kx0
3+ asP&n
{3 o%d:
public synchronized int write(byte[] b,int nStart,int nLen) /0\QL+^!
{ HD00J]y_
int n = -1; 4*8&[b
try{ dq1TRFu
oSavedFile.write(b,nStart,nLen); j+0.=#{??
n = nLen; U.Hdbmix
} fI}c 71b`
catch(IOException e) %!wq:~B1
{ &;U|7l~vl
e.printStackTrace (); gz\j('~-D
} K+> V|zKuk
B1,?{Ur
32y[
return n; M,G8*HI"
} `,-STIh)
x!+Z{x
}200g_^
} #M:B3C!ouY
m5qCq9Y
/j %_t
/* d+1x*`U|
**SiteInfoBean.java gvr]]}h:O
*/ c}cG<F
package NetFox; %&1$~m0
E7LbSZ
hg&u0AQ2
public class SiteInfoBean { hXnw..0"
gix>DHq$k
_UIgRkl.
private String sSiteURL; //Site's URL +gNX7xuY
private String sFilePath; //Saved File's Path )|:8zDuJ
private String sFileName; //Saved File's Name J~'~[,K
private int nSplitter; //Count of Splited Downloading File ](n69XX_
!ABLd|tP
k!vHO
public SiteInfoBean() X&,N}9>B
{//nSplitter的缺省值为5 >vxWx[fRu
//default value of nSplitter is 5 )BpIxWd?
this("","","",5); vVdxi9yk
} _KxX&THaj
ku-cn2M/
{[lx!QF 8&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V^WQ6G1
{ R05T5Q1]A
sSiteURL= sURL; 6Ok,_ !
sFilePath = sPath; 9JXhHAxD
sFileName = sName; `>y[wa>9r
this.nSplitter = nSpiltter; 8(uw0~GO
K)N)IZ1q
Sy:K:Z|[U
} 9<w=),R`8
`U!(cDY
G\uU- z$)
public String getSSiteURL() W n6,U=$3
{ IY~ {)X
return sSiteURL; 5@iy3olP
} Sn0Xl3yr
sB8p( L
%'kX"}N/
public void setSSiteURL(String value) epYj+T
{ +O,V6XRr
sSiteURL = value; Ho>p ^p
} QdirE4W
p>!1S
(\tq<h0
public String getSFilePath() FfjC M7?
{ WEps.]s
return sFilePath; }il%AAI9}r
} cS5w +`,L
^`/V i
C\J@fpH(t`
public void setSFilePath(String value) Y'?Iznb
{ EJv!tyJ\[
sFilePath = value; 5#P: "U
} ]m RF[b$
}@3$)L%n_u
:^K~t!@
public String getSFileName() %odw+PhO
{ xL|?(pQ/BK
return sFileName; Mi<*6j0
} i4 P$wlO
$`ON!,oa
B>R* f C@g
public void setSFileName(String value) 20n%o&kG]8
{ oUCS|
sFileName = value; sek6+#|=
} HH+TjX/b
Qb@BV&^y&
d"z*Nb
public int getNSplitter() B6-AIPb
{ |WQD=J%~(
return nSplitter; Ni&,g
} So0`c,D
_Wq7U1v`
}'%$7vL`Ft
public void setNSplitter(int nCount) kg zwlKK
{ CzK%x?~]
nSplitter = nCount; #@IQlqJfY7
} 4GEjW4E
} jBT*~DyN z
w6%l8+{R
wHq('+{=&
/* r#ks>s
**Utility.java #d3[uF]OmW
*/ AX/=}G
package NetFox; &mCs%l
\?aOExG I
hg(KNvl
public class Utility { 3L%Y"4(mm
D "JMSL4r
;]|m((15G
public Utility() BASO$?jf4
{ N)`tI0/W
44z=m MR<
VG? yL2y
} A)=X?x
}Ox2olUX
//线程睡眠 Z`e$~n(Bh
public static void sleep(int nSecond) AEBw#v!,o
{ *9\oD~2Y
try{ #1gTpb+t
Thread.sleep(nSecond); 9?EY.}~
} LPtx|Sx![
catch(Exception e) +# m
{ F[Qsv54
e.printStackTrace (); C6Um6X9/i
} {6REfY c
} @`#OC#
P1M|f4*
//日志 +:j4G^V
public static void log(String sMsg) GA({ri
{ 0b!fWS?,k0
System.err.println(sMsg); \Qe'?LRu{
} x'VeL|
$u/8Rp
W+fkWq7`Xx
public static void log(int sMsg) zW|$x<M^
{ LA(f]Xmc
System.err.println(sMsg); XyN`BDFi
} _p3WE9T
} cx,u2~43A&
,i1fv "
9 ayH:;
/* O% j,:t'"
**TestMethod.java }[YcilU_
*/ Cf8R2(-4
package NetFox; lk5_s@V l
$\=6."R5<
w+:+r/!g
public class TestMethod { F!DrZd>\
YB(#]H|8S
L>|A6S#y8/
public TestMethod() fh/)di
{ ///xx/weblogic60b2_win.exe wFH(.E0@Q
try{ XmE_F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nJnO/~|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5cv, >{~5
SiteFileFetch fileFetch = new SiteFileFetch(bean); r)*_,Fo|
fileFetch.start(); zXA= se0U
} n~L'icD[
catch(Exception e){e.printStackTrace ();} [xH2n\7
IWSEssP
av$\@4I
} 2g`uC}
@=^jpSnZ
vCrWA-q#
public static void main(String[] args) QQ2OZy>W
{ #EwRb<'Em
new TestMethod(); @idp8J [td
} O>{t}6o
} 8DmX4*
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