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)); qXW\/NT"p<
} H\ejW@<;h
for(int i=0;i<nEndPos.length-1;i++) 6^]|
{ zg<-%r'$
nEndPos = nStartPos[i+1]; fx_#3=bXi
} |^1U<'oM#
nEndPos[nEndPos.length-1] = nFileLength; 8J(j}</>a
} g;63$_<
} w_56y8Pd4
8~o']B;lJ
eA4:]A"
//启动子线程 W%g*sc*+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vAUt~X"
for(int i=0;i<nStartPos.length;i++) SO0\d0?u
{ >s{I@#9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f)/Z7*Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C:J;'[,S
nStartPos,nEndPos,i); Z;.-UXat
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :*''ci
fileSplitterFetch.start(); }]vUr}Els
} =#G 2}8mQD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e,p"=/!aY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r<+C,h;aww
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o]e,5]
nEndPos = " + nFileLength); &n k)F<
// fileSplitterFetch[nPos.length-1].start(); !2LX+*;
Ht Fr(g\"$
!,Uo{@E)Y
//等待子线程结束 7=6:ZSI
//int count = 0; b&z#ZY
//是否结束while循环 JY0aE
boolean breakWhile = false; `>:5[Y
?.?)5 &4
b{A[\ "
while(!bStop) \]tBwa
{ v/`D0g-uX)
write_nPos(); ob.<j
Utility.sleep(500); B@,r8)D
breakWhile = true; r<`:Q]
rQjk
) O0Cz n
for(int i=0;i<nStartPos.length;i++) cbzA`b'Mg
{ E=sh^Q(A
if(!fileSplitterFetch.bDownOver) ;.>*O oe&
{ \<LCp;- K
breakWhile = false; \QvGkcDc{
break; sl'4AK~\
} Qd}n4KF\
} Y <6|z3
if(breakWhile) 7~h3B<
break; %F*9D3^h
]>n{~4a
dN{At-
//count++; HsCL%$k
//if(count>4) b;i*}4h!
// siteStop(); -^@FZR^Y
} "Lp.*o
xWLvx'8W
Za|7gt];l
System.err.println("文件下载结束！"); V}E['fzBFV
} 5aQ)qUgAW
catch(Exception e){e.printStackTrace ();} Xb_ V\b0
} yzS]FwW7
Y+-yIMt$r
U2VEFm6
//获得文件长度 46?z*~*G
public long getFileSize() #7uH>\r
{ VUP|j/qD
int nFileLength = -1; *p{p.%Qs:
try{ BtJkvg(2]
URL url = new URL(siteInfoBean.getSSiteURL()); P;5)Net1X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }z]d]
httpConnection.setRequestProperty("User-Agent","NetFox"); )vtbA=RH?
9{pT)(Wnb
RoqkT|#$
int responseCode=httpConnection.getResponseCode(); mR0`wrt
if(responseCode>=400) vl (``5{
{ (Jq m9
processErrorCode(responseCode); 6i/unwe!`)
return -2; //-2 represent access is error *l7 `C)
} d?oXz|;H(
!'$*Z(
[}L?EM
String sHeader; Dl!0Hl
rJ/HIda
\`k=9{R.
for(int i=1;;i++) '(K4@[3t
{ HNkOPz+d&8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :(q4y-o6
//Utility.log(in.readLine()); J.iz%8
sHeader=httpConnection.getHeaderFieldKey(i); Uw4iWcC
if(sHeader!=null) 0Gu77&
{ [n9l[dN
if(sHeader.equals("Content-Length")) C:1(<1K
{ @3n!5XM{EE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2I:P}!
break; sI\NX$M
} ;(K/O?nrJ
} 3[#^$_96b
else Bo:epus}\
break; %)V=)l.j
} F6vsU:TfB
} -#%M,Qb
catch(IOException e){e.printStackTrace ();} :V(C+bm *
catch(Exception e){e.printStackTrace ();} }w)}=WmD
I=DVMG|
Ry[7PLn]
Utility.log(nFileLength); 2dz)rjdO,
x|Uwk=;X|s
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return nFileLength; H[w';u[%
} / 0$!.
5CnNp?.t^
@o[ZJ4>*
//保存下载信息（文件指针位置） W,8Uu1X =
private void write_nPos() x`?>j$
{ &NF$_*\E
try{ gwNZ`_Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); |i B#
output.writeInt(nStartPos.length); fFEB#l!oUb
for(int i=0;i<nStartPos.length;i++) *X3wf`C?
{ w[a(I}x
// output.writeLong(nPos); U:x;4
output.writeLong(fileSplitterFetch.nStartPos); Xcfd]29
output.writeLong(fileSplitterFetch.nEndPos); wv3*o10_w8
} q%d,E1
output.close(); ebEI%8p g
} "E<+idoz
catch(IOException e){e.printStackTrace ();} \e'Vsy>q
catch(Exception e){e.printStackTrace ();} nK< v
} zw'%n+5m
V+D<626o
it{Jd\/hR
//读取保存的下载信息（文件指针位置） {'alA
private void read_nPos() ftmPdha%+
{ nh7_ jEX
try{ UvMkL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _zbIS&4
int nCount = input.readInt(); ,J2qLH1
nStartPos = new long[nCount]; NPv.7,
nEndPos = new long[nCount]; w\[l4|g`
for(int i=0;i<nStartPos.length;i++) ?9?A)?O<j~
{ 7oZPb
nStartPos = input.readLong(); z\FBN=54z
nEndPos = input.readLong(); 4'3;{k$z
} {1=|H$wKg
input.close(); %4` U' j
} O\uIIuy
catch(IOException e){e.printStackTrace ();} {tYY _BI<
catch(Exception e){e.printStackTrace ();} $S>bcsAy
} *Mg@j;+5s
).HA#!SE
qu#xc0?
private void processErrorCode(int nErrorCode) m*1
{ {a\! 1~
System.err.println("Error Code : " + nErrorCode); ,ye[TQ\,M
} VJ h]j(
m|B)A"Sm
}>y!I5O
//停止文件下载 YeT{<9p
public void siteStop() K%`]HW@I{
{ C ]B P}MY<
bStop = true; qh W]Wd"g
for(int i=0;i<nStartPos.length;i++) b IxH0=f
fileSplitterFetch.splitterStop(); P )oNNY6}
Y(aUB$"
#Rfcp!
} #|+4`Gf^
} tf54EIy5Y
//负责部分文件的抓取 Q"NZE
**FileSplitterFetch.java f.j<VKF}
*/ A ?tna6W:
package NetFox; A|K=>7n]U
h$sOJs~6h
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import java.io.*; "]2^O
import java.net.*; JXRU9`3)A
u,:hT] ~+
GL>YJ%
public class FileSplitterFetch extends Thread { Yx,E5}-
zC:Pg4=w]
=mX26l`B
String sURL; //File URL nT01B1/<]
long nStartPos; //File Snippet Start Position %hmRh~/&
long nEndPos; //File Snippet End Position A#K<5%U{Mv
int nThreadID; //Thread's ID J9t?;3
boolean bDownOver = false; //Downing is over 1D)0\#><
boolean bStop = false; //Stop identical hMz)l\0
FileAccessI fileAccessI = null; //File Access interface `zq+Xl
z{ M2tLNb
' A+L #
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException PPy~dp
{ YH+(N
this.sURL = sURL; Uu*iL< `
this.nStartPos = nStart; &Qv HjjQ?u
this.nEndPos = nEnd; K0oF=|
nThreadID = id; xR$T/]/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f`;w@gR`=
} [f {qb\
X}]A_G
x'?p?u~[
public void run() SAitufS
{ "~.4z,ha
while(nStartPos < nEndPos && !bStop) Yh^8 !
{ RiAMW|M"C
$"( 15U
0=U|7%dOL
try{ $8(QBZq
URL url = new URL(sURL); a_0I)' ?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )l! /7WKY
httpConnection.setRequestProperty("User-Agent","NetFox"); u^MRKLn
String sProperty = "bytes="+nStartPos+"-"; 0#=xUk#LP`
httpConnection.setRequestProperty("RANGE",sProperty); 7f k)a
Utility.log(sProperty); ~a4Y8r
ex`T9j.=B
pl[@U<8aw
InputStream input = httpConnection.getInputStream(); F =*4]O
//logResponseHead(httpConnection); }%PK %/ zI
S"?fa)~
|ssl0/nk
byte[] b = new byte[1024]; IUEpE9_
int nRead; #^]vhnbN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _OjZ>j<B.
{ .Mb0++% W
nStartPos += fileAccessI.write(b,0,nRead); ){)-}M
//if(nThreadID == 1) =Yl ea,S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YL!{oHs4
} ' =5B
smQl^ 6a
Nr]Fh
Utility.log("Thread " + nThreadID + " is over!"); Sx J0Y8#z
bDownOver = true; oj{CNa
//nPos = fileAccessI.write (b,0,nRead); \1<|X].jNY
} __7}4mA
catch(Exception e){e.printStackTrace ();} cNwHY Z'
} ~@6l7H6{
} ?aWVfX!+G5
EFx>Hu/[G
'nM4t
//打印回应的头信息 Ye$j43b
public void logResponseHead(HttpURLConnection con) sCt)Yp+8}B
{ <FU?^*~
for(int i=1;;i++) <)!,$]S
{ <"K*O9nst
String header=con.getHeaderFieldKey(i); *U%3[6hm
if(header!=null) H#V&5|K%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >EFWevT{
Utility.log(header+" : "+con.getHeaderField(header)); p[xGL } +\
else yZ[g2*1L
break; N>*+Wg$Ne
} U/kQwrM
} _A!Fp0}`
<},JWV3
6|B9kh}
public void splitterStop() 1,) yEeHjU
{ >w7KOVbN3
bStop = true; ^<-r57pz
} @q>Hl`a
M!i|,S
\5!7zPc
} NZ i3U
ToPjBvD
"OwVCym?
/* a,S;JF)v
**FileAccess.java <>{m+=gA
*//文件访问(定位，写) MYjc6@=cR
package NetFox; (?t}S.>g
import java.io.*; +e2:?d@
7M7Ir\d0lp
A&Aj!#
public class FileAccessI implements Serializable{ S:}"gwFM
&*7KQd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9NU0K2S
RandomAccessFile oSavedFile; Kw?3joy
long nPos; /u.ZvY3,
-j]k^
jMTM:~0N
public FileAccessI() throws IOException /N_:npbJF
{ LOi}\O8
this("",0); wxc#)W
} I-r+1gty
wz69Yw7
OrM1eP"I
public FileAccessI(String sName,long nPos) throws IOException 54z.@BJhE
{ J@$~q}iG
oSavedFile = new RandomAccessFile(sName,"rw"); !*"fWahv
this.nPos = nPos; B T"R"w
oSavedFile.seek(nPos); +ppA..1
} a=j'G]=
u)<s*jk
-c0ypz
public synchronized int write(byte[] b,int nStart,int nLen) 7>j~;p{
{ {LF4_9 =
int n = -1; CKK}Z;~:
try{ ]r|oNGD)G
oSavedFile.write(b,nStart,nLen); :[_msd
n = nLen; 1 rhZlmf[r
} "t.`/4R2w
catch(IOException e) q{Z#}|km#
{ < z2wt
e.printStackTrace (); A)C)5W
} @lE'D":?
/ }$n_N\!)
|0=UZK7%O
return n; ,n8\y9{G
} sNo8o1Hby
i}DS+~8v
[A,^F0:h
} @pYEzizP7
rT/r"vr
PZusYeV8b
/* *l+Dbm,u
**SiteInfoBean.java + tMf&BZ
*/ \$wkr
package NetFox; 0Z8"f_GK
E(PBV
8\lh'8
public class SiteInfoBean { ciS,
=zyA~}M2
BtC*]WB"_'
private String sSiteURL; //Site's URL R03 Te gwA
private String sFilePath; //Saved File's Path DaQl ip
private String sFileName; //Saved File's Name R);Hd1G
private int nSplitter; //Count of Splited Downloading File ~bhS$*t64
LjBIRV7
be,Rj,-
public SiteInfoBean() 3J+2#ML
{//nSplitter的缺省值为5 @;bBc
//default value of nSplitter is 5 >SK:b/i
this("","","",5); (6S'wb
} +1y$#~dl
]A3
t+8e?="
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \c:$eF
{ '*b]$5*p
sSiteURL= sURL; h<LFTYE@
sFilePath = sPath; =+!l8o&o,
sFileName = sName; 3OZPy|".ax
this.nSplitter = nSpiltter; K] (*l"'U5
1g{Pe`G,
C}RO'_Pq
} 2]5{Xmmo9
XnQR(r)pR2
W#p7M[
public String getSSiteURL() -[=eVS.2%
{ CBEf;Ig
return sSiteURL; r0XEB,}
} 2jFuF71
u S1O-Q>
}xk(aM_
public void setSSiteURL(String value) 3#>W\_FY*D
{ oBkhb
sSiteURL = value; p%3z*2,(
} At iUTA
!@=S,Vc.
$8=|<vt
public String getSFilePath() } a9Ah:.7/
{ R c+olJ^5
return sFilePath; T-en|.
} ^viabkf C
V\;Xa0
_B0(1(M<2
public void setSFilePath(String value) \wK&wRn)
{ f"ndLX:'}
sFilePath = value; q!ZM Wg
} {]T?)!Vm
@Vre)OrN#
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public String getSFileName() Ek_5% n
{ hIJtu;}zU
return sFileName; }5;4'l8
} >rCD5#DG
{o}U"b<+Ra
y|5L%,i
public void setSFileName(String value) I=y7$+7%
{ ><<>4(eF p
sFileName = value; @NLcO}
} 9n& &`r
?b;2PH"
$Nu{c;7"
public int getNSplitter() F8f}PV]b
{ .[Sis<A]%
return nSplitter; 1M]=Nv
} w4U,7%V
y{%0[x*N<m
s#9q3JV0
public void setNSplitter(int nCount) 3p0v
{ MCKN.f%lP
nSplitter = nCount; g#J`7n
} PI9,*rOy
} UMoj9/-
}L\;W:0
$UR:j8C{p$
/* ^_WR) F'K
**Utility.java hNN>Pd~;
*/ EeW ,-I
package NetFox; -S'KxC
!5`MiH
.-d'*$ yJ
public class Utility { xXe3E&
1BSd9Ydj
B9maz"lJ
public Utility() XO+BZB`F
{ M/N8bIC! Q
vO}r(kNJ
PG&t~4QM`
} _~<sb,W
e"E8BU
//线程睡眠 $.PRav
public static void sleep(int nSecond) RM;a]g*
{ g#5R||r
try{ }"D;?$R!
Thread.sleep(nSecond); ?I}RX~Tgg
} G:AA>t
catch(Exception e) 5\Q Tm;
{ p*;!5;OUR
e.printStackTrace (); 'nCVjO7o
} AV5={KK
} [wGj?M}
%K6veB{M
//日志 c1#0o)q*7
public static void log(String sMsg) Xw?DN*`L
{ nK>CPqB^(
System.err.println(sMsg); YX$(Sc3.6
} '+88UFSq5
$ev+0m_
Bqf(6\)F
public static void log(int sMsg) w*F[[*j@.
{ CX|W$b)%
System.err.println(sMsg); zI`I Q
} J"`VA_[
} @<\oM]jX
(GJtTp~2C4
k@4N7}
/* U=Ps#
**TestMethod.java .j]tzX
*/ j4$nr=d.6
package NetFox; PLCm\Oh$l
GA^hev
? i{?Q,
public class TestMethod { R"B{IWQi
.5|[gBK
>?$2`I
public TestMethod() sscbf
{ ///xx/weblogic60b2_win.exe 5YY5t^T
try{ Z& _kq|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x[0T$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )+_Vx}O:}
SiteFileFetch fileFetch = new SiteFileFetch(bean); qG9a!sj
fileFetch.start(); KF%BX~80C
} _*mn4n=
catch(Exception e){e.printStackTrace ();} P5Xp #pa
$qNF /rF
IiPX`V>RC
} [\8rh^LFi
VGS%U8;
L!}!k N:?
public static void main(String[] args) JW>k8QjyN
{ CIW4E
new TestMethod(); 6.@.k
} m{IlRf'
} zMSwU]4I!
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