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)); E=nIRG|g
} s.$3j$vT 8
for(int i=0;i<nEndPos.length-1;i++) sS*3=Yh
{ U|jSa,}
nEndPos = nStartPos[i+1]; 4 o Fel.o
} h&KO<>
nEndPos[nEndPos.length-1] = nFileLength; j0oR)du
} k$blEa4
} sB7# ~pA
i<#QW'R(
.%xn&3
//启动子线程 A1O'|7X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MN\HDKN
for(int i=0;i<nStartPos.length;i++) >T^;MS
{ jIJ~QpNE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t'n pG}`tE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2LF/H$]o5
nStartPos,nEndPos,i); \NPmym_6J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JMC. w!
fileSplitterFetch.start(); fp`;U_-&0
} ;ub;lh3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V<GHpFi0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X $jWo@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZOh`(})hy
nEndPos = " + nFileLength); b,7k)ND1F
// fileSplitterFetch[nPos.length-1].start(); EJMM9(DQ7
,o86}6Ag
B38]~'8
//等待子线程结束 l9{hq/V
//int count = 0; GeH#I5y
//是否结束while循环 g6j?,c|y
boolean breakWhile = false; 9jM}~XvV
H\ F:95
Lt64JH^lz
while(!bStop) (A9Fhun
{ 0X6YdW_2X
write_nPos(); +^60T$
Utility.sleep(500); geru=7
breakWhile = true; LBYMCY
m*&]!mM"0G
o#3ly-ht
for(int i=0;i<nStartPos.length;i++) aTH{'mN
{ +$ 'Zf0U
if(!fileSplitterFetch.bDownOver) &u$Q4
{ 'DP1,7
breakWhile = false; 75T%g!c#
break; u^^[Q2LDU}
} 5_GYrR2
} ?:Uv[|S#>
if(breakWhile) {$0mwAOH "
break; DX#Nf""Pw
<cps2*'
~Y^+M*
//count++; Sc]B#/~B
//if(count>4) +}Dw3;W}m
// siteStop(); \ 2M_\Q`NY
} |jGf<Bf5
rBQ_iB_
3dg1DR;
System.err.println("文件下载结束！"); ^O?/yV?4c
} !|S(Ms
catch(Exception e){e.printStackTrace ();} 8W*%aOi5+
} =W(Q34
n\mO6aJ
(S>C#A=E\
//获得文件长度 ,0M_Bk"
public long getFileSize() V(H1q`ao9
{ )}Hpi<5N
int nFileLength = -1; B-*+r`@Bd
try{ Ua:}Vn&!
URL url = new URL(siteInfoBean.getSSiteURL()); ^UP`%egR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &GpRI(OB/+
httpConnection.setRequestProperty("User-Agent","NetFox"); YL!P0o13r
g];!&R-
p_RsU`[
int responseCode=httpConnection.getResponseCode(); >^u2cAi3[
if(responseCode>=400) Snj'y,p[
{ ~[t[y~Hup
processErrorCode(responseCode); Cjn#00
return -2; //-2 represent access is error b6,iZ+]
} `'DmDg
5AFJC?
`+]Qz =}
String sHeader; (p"%O
4>wP7`/+y
R$R*'l
for(int i=1;;i++) Zu*F#s!tUI
{ m+=] m_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8SMxw~9$
//Utility.log(in.readLine()); s:n6rG
sHeader=httpConnection.getHeaderFieldKey(i); S\CCrje
if(sHeader!=null) ?qb}?&1
{ 2=*H 8'k
if(sHeader.equals("Content-Length")) OAgniLv
{ u+9hL4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k R?qb6
break; 1I%w?^sm_
} /ixp&Z|7
} Akq2 d;
else NDN7[7E
break; nGC/R&
} =>m<GvQz
} {a =#B)6
catch(IOException e){e.printStackTrace ();} W_JlOc!y
catch(Exception e){e.printStackTrace ();} ld[I}88$
3/P1!:g9
'+@=ILj>
Utility.log(nFileLength); akmkyrz'&
$zUP?Gq!
=O~_Q-
return nFileLength; em y[k
} J"0`%'*/
Sh/08+@+L:
.#EFLXs
//保存下载信息（文件指针位置） 0HZ{Y9]
private void write_nPos() 8'[~2/
{ (^ JI%>
try{ b!+hH Hv:
output = new DataOutputStream(new FileOutputStream(tmpFile)); -M\<nx
output.writeInt(nStartPos.length); 4j-Xi
for(int i=0;i<nStartPos.length;i++) l5~os>
{ d9k0F OR1
// output.writeLong(nPos); zrvF]|1UP
output.writeLong(fileSplitterFetch.nStartPos); 1a/++4O.|
output.writeLong(fileSplitterFetch.nEndPos); YX!iL6?~
} N"Z{5A
output.close(); 2IK}vDsis
} %U/(|wodd
catch(IOException e){e.printStackTrace ();} &j;wCvE4+
catch(Exception e){e.printStackTrace ();} ez7A4>/
} R8K&R\
%:i7s-0w
<;lkUU(WT2
//读取保存的下载信息（文件指针位置） [|v][Hwv
private void read_nPos() \P[Y`LYL
{ )j6~Wy@4
try{ ]>!K3kB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }H53~@WP>
int nCount = input.readInt(); oe^I
nStartPos = new long[nCount]; 9p]QM)M
nEndPos = new long[nCount]; HVRZ[Y<^
for(int i=0;i<nStartPos.length;i++) Usvl}{L[
{ p#-Z4-`
nStartPos = input.readLong(); rm7ANMB:
nEndPos = input.readLong(); [z:!j$K
} &0d#Y]D4`
input.close(); x5pdS:
} _T60;ZI+^
catch(IOException e){e.printStackTrace ();} 'B|JAi?
catch(Exception e){e.printStackTrace ();} 6%'QjwM_
} u*eV@KK!
/l3V3B7
7^avpf)>
private void processErrorCode(int nErrorCode) 0S"mVZ*P
{ hDDn,uzpd
System.err.println("Error Code : " + nErrorCode); J4hL_iCQ
} fuW\bo3
U4'#T%*
w?L6!)oiz
//停止文件下载 #<fRE"v:Q
public void siteStop() p%ki>p )E|
{ gt)I(
bStop = true; Xg6Jh``
for(int i=0;i<nStartPos.length;i++) soxc0OlN
fileSplitterFetch.splitterStop(); yxPazz
2Ah#<k-gC;
{p2!|A&a
} +|3@=.V
} RHW]Z Pr<
//负责部分文件的抓取 AI2)g1m
**FileSplitterFetch.java z^B,:5Tt
*/ D\v+wp.
package NetFox; +Ze}B*0
hPkp;a #
iI T;K@&
import java.io.*; iT+8|Yia
import java.net.*; #\{l"-
E_rI?t^
Fe*R
public class FileSplitterFetch extends Thread { .^`{1%
u,ho7ht3(
WCZjXDiwJ
String sURL; //File URL :U|1xgB
long nStartPos; //File Snippet Start Position )rU
long nEndPos; //File Snippet End Position e+7"/icK
int nThreadID; //Thread's ID u[;\y|75
boolean bDownOver = false; //Downing is over NWESP U):w
boolean bStop = false; //Stop identical 0D.Mke )
FileAccessI fileAccessI = null; //File Access interface Oi.C(@^(
tAd%#:K
,L2ZinU:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l\H=m3Bg
{ d0!5j
this.sURL = sURL; 5Pc;5 o0C
this.nStartPos = nStart; 8Al{+gx@?
this.nEndPos = nEnd; r8?gD&c}
nThreadID = id; 8 /]S^'>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :LQYo'@yB
} g/d<Zfq<{
Vr)S{k-Q
gx/,)> E.
public void run() =ZznFVJ`={
{ 2QcOR4_V
while(nStartPos < nEndPos && !bStop) Evq IcZ
{ J[|y:N
y-b%T|p9
1s&zMWC
try{ u/0h$l
URL url = new URL(sURL); k9R4Y\8P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NN{?z!
httpConnection.setRequestProperty("User-Agent","NetFox"); yPBZc h%-
String sProperty = "bytes="+nStartPos+"-"; .NC!7+1m
httpConnection.setRequestProperty("RANGE",sProperty); s]0{a.Cpv
Utility.log(sProperty); !PlEO 2at
Dj?> <@
bHnT6Icom
InputStream input = httpConnection.getInputStream(); nc29j_Id
//logResponseHead(httpConnection); e2Pcm_Ahv*
q9K)Xk$LF
|3b^~?S
byte[] b = new byte[1024]; r|8d 4
int nRead; k .;j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a.\:T,cP>
{ 3ZPWze6
nStartPos += fileAccessI.write(b,0,nRead); sE<V5`Z=
//if(nThreadID == 1) 7aRi5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !*&V-4
} Pj^{|U21
05#1w#i
PdFKs+Z`
Utility.log("Thread " + nThreadID + " is over!"); F,F4nw<W
bDownOver = true; qA7>vi%
//nPos = fileAccessI.write (b,0,nRead); k"%~"9
} eKgBy8tNS0
catch(Exception e){e.printStackTrace ();} p4rL}Jm&
} ;`4&Rm9n?
} >2)OiQ`zg
DPxM'7
r,3DTBe
//打印回应的头信息 ?3,:-"(@p
public void logResponseHead(HttpURLConnection con) jOunWv|
{ ZQsJL\x[UK
for(int i=1;;i++) 1=c\Rr9]
{ ZU4nc3__
String header=con.getHeaderFieldKey(i); ,-c6dS
if(header!=null) OZF rtc+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M)+H{5bt
Utility.log(header+" : "+con.getHeaderField(header)); /Iy]DU8
else A`$%SVgFV^
break; ^mDe08. %b
} VcYrK4
} ek\ xx
rU:`*b<
8W(*~}ydYY
public void splitterStop() Vb;*m5,?:
{ t9`.bx8
bStop = true; dq6m>;`
} _/$Bpr{R
(N6i4 g6
kZ .gO
} sf qL|8
\ a<h/4#|
k,6f &#x
/* jD]~ AwRJ
**FileAccess.java N^G Mp,8
*//文件访问(定位，写) J?1 uKR
package NetFox; ::lKL
import java.io.*; wu!59pL
r'r%w#=`t
{hjhL: pg
public class FileAccessI implements Serializable{ %P/Jq#FE.
S(lO(gY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )p0^zv{
RandomAccessFile oSavedFile; l`{\"#4
long nPos; CS5?Ti6
'RR~7h
(,Q7@s
public FileAccessI() throws IOException ;-lXU0}&
{ .Iw AK/QS
this("",0); drP=A~?&:
} X*XZb F"=
KnQ*vM*VM
Jy:Qlx`
public FileAccessI(String sName,long nPos) throws IOException gQg"j)
{ py!|\00}
oSavedFile = new RandomAccessFile(sName,"rw"); t;Sb/3
this.nPos = nPos; )h4f\0
oSavedFile.seek(nPos); 5"@*?X K^
} Ad8n<zt|
wLH>:yKUU
bKY7/w<dP
public synchronized int write(byte[] b,int nStart,int nLen) gIa+5\qYY
{ )3}9K ^jS
int n = -1; )JLdO*H
try{ nI-w}NQ
oSavedFile.write(b,nStart,nLen); g"DG]/ev
n = nLen; *boR`[Ond
} SiRaFj4s"
catch(IOException e) KIf dafRL
{ gMmaK0uhS
e.printStackTrace (); eS\Vib
} SCHP L.n
vn!3l1\+J
5h-SCB>P
return n; Tod&&T'UW
} &\WSQmtto
BC#C9|n
xp)sBM7A
} T{.pM4Hd
?m}s4a
3>AMII
/* /{aj}M0kN
**SiteInfoBean.java `l ^9/_g'6
*/ L-WT]&n_
package NetFox; )._;~z!
Fn;SF4KOm
q4:o#K#
public class SiteInfoBean { ,+DG2u
8,4"uuI
{ ]{/t-=
private String sSiteURL; //Site's URL /<=u\e'rE
private String sFilePath; //Saved File's Path QL&ZjSN
private String sFileName; //Saved File's Name ]Ji.Zk
private int nSplitter; //Count of Splited Downloading File v5#jZ$<F
uM IIYS
feDlH[$
public SiteInfoBean() t ;;U}
{//nSplitter的缺省值为5 q460iL7yF}
//default value of nSplitter is 5 EzM ?Nft
this("","","",5); N=5a54!/
} w!-gJmX>
O|{d[eX
8B K(4?gC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qFCOUl
{ xw,IJ/E$1
sSiteURL= sURL; |O\s|H
sFilePath = sPath; iAEbu&XG
sFileName = sName; +US!YU
this.nSplitter = nSpiltter; :Uzm
M#4pE_G
)9{0]u;9
} \^J%sf${
(&F}/s gbi
XH4
public String getSSiteURL() %+W{iu[|
{ _~l5u8{^6
return sSiteURL; ;;OAQ`
} O>bC2;+s
X1x#6 oi
.PIL +x*]N
public void setSSiteURL(String value) BDW^7[n
{ X8a/ `Y,
sSiteURL = value; s^G.]%iU
} A@!qv#'
'j8:vq^d
ar!R|zmf
public String getSFilePath() 58tARLDr
{ *k(XW_>
return sFilePath; y*jp79G
} jjB~G^n
m<T%Rb4?@
O~#!l"0 L+
public void setSFilePath(String value) `!;_ho
{ gZ3u=uME
sFilePath = value; Xv5wJlc!d
} D[[|")Fn
r"gJX
^B.5GK)!
public String getSFileName() p?%y82E
{ c \J:![x
return sFileName; ul6]!Iy
} qdJ=lhHM}
?4#Li~q
F4-$~v@
public void setSFileName(String value) K*vt;L
{ In"ZIKaC
sFileName = value; @su^0 9n
} |/|5UiX7
b5dD/-Vj
7UKh688
public int getNSplitter() KI iO
{ 6EoMt@7g
return nSplitter; O-0x8O^B
} ?DS@e@lx
fM :]&
(?1y4M
public void setNSplitter(int nCount) B?gOHG*vd>
{ $Ps|HN
nSplitter = nCount; Af~$TyX
} >^?u .gM3
} `t>l:<@%
iJ)_RSFK
9IdA%RM~mH
/* >UTBO|95y
**Utility.java #K_ii)n
*/ [B*x-R[FI
package NetFox; HTv2#
}<0BX\@I
}^~F|
public class Utility { !I{0 _b{
p}z<Fdu0
hn7# L
public Utility() ~f&E7su-6+
{ +/4A
64 wv<r]5j
}1L4"}L.
} )Yh+c=6 ?
38Mv25N
//线程睡眠 x}wG:K
public static void sleep(int nSecond) a_^\=&?'
{ /Vx7mF:
try{ HYD'.uj
Thread.sleep(nSecond); B-Ll{k^
} ]`!>6/[
catch(Exception e) ,a{P4Bq
{ ;IvY^(YS@;
e.printStackTrace (); 8rAg\H3E
} ?8H8O %Z8
} G/y5H;<9M
]!W=^!
//日志 A_"w^E{P
public static void log(String sMsg) U|H=Y"pL
{ 6##_%PO<m
System.err.println(sMsg); ;0]aq0_#(
} xk9%F?)
IEL%!RFG
6fE7W>la
public static void log(int sMsg) [t m_Mg
{ bi',j0B
System.err.println(sMsg); XFVE>/H
} KC*e/J
} y;m|
i<C*j4qQ
UP$.+<vm
/* w8")w*9Lmg
**TestMethod.java 9d0@wq.
*/ =g7x' kN
package NetFox; ;Zcswt8]u
ih-#5M@
gMi0FO'
public class TestMethod { ]\-A;}\e
ch*8B(:
>4x(e\B
public TestMethod() { T/[cu<
{ ///xx/weblogic60b2_win.exe X~bX5b[P
try{ B-RjMxX4>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y,qI@n<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hk;5w{t}}
SiteFileFetch fileFetch = new SiteFileFetch(bean); h]5(].
fileFetch.start(); Q^P}\wb>
} 9 &dtd
catch(Exception e){e.printStackTrace ();} '0;l]/i.
^ox=HNV
j.[.1G*("
} zF`0J
&Q/W~)~
F>Ah0U0
public static void main(String[] args) _O)>$.^6
{ :I]Mps<
new TestMethod(); B9_X;c
} !NK1MU?T)
} ~Py`P'+
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