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)); -sO EL{
} /c/!13|
for(int i=0;i<nEndPos.length-1;i++) MnKEZ: 2
{ nUmA
nEndPos = nStartPos[i+1]; ErB6fl
} @[zPN[z.
nEndPos[nEndPos.length-1] = nFileLength; /RmLV
} fLc<}DF
} bLu6|YB
JS&l h
&#.XLe\y
//启动子线程 G7%Nwe~Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y+Q!4A
for(int i=0;i<nStartPos.length;i++) p`{<q -
{ 0plRsZ}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k6[t$|lMy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l:Ci'=
nStartPos,nEndPos,i); TKoO\\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N Ja]UZx
fileSplitterFetch.start(); {+ [rJ_
} 3dadeu^{A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,PRM(n-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =h&DW5QC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f`WmRx]K
nEndPos = " + nFileLength); plfz)x3
// fileSplitterFetch[nPos.length-1].start(); X~GZI*P
FjiLc=RXXz
}}t"^ms
//等待子线程结束 hpWAQ#%oHm
//int count = 0; ]N1$ioC#
//是否结束while循环 qK|r+}g|&
boolean breakWhile = false; A!iH g__/t
4CX*
S)g5Tu)
while(!bStop) BHZGQm
{ s}|IRDpp
write_nPos(); o>U%3-+T^J
Utility.sleep(500); w^R5/#F_r
breakWhile = true; =*Wl;PI'
XZp(Po:H
q#sMew\{
for(int i=0;i<nStartPos.length;i++) UfcM2OmbK
{ U0jq.]P
if(!fileSplitterFetch.bDownOver) &??(EA3
{ 5Odi\SJ&
breakWhile = false; oH6(Lq'q
break; n6Q 3X
} lt,x(2
} s)/i_Oe$\
if(breakWhile) &lI.N~Ao
break; n)`*{uv$
+/Y)s5@<
zb9d{e
//count++; h3@mN\=h'
//if(count>4) n=rPFpRLF
// siteStop(); T^A:pL1
} /"iYEr%_
6mRvuJ%
A*\4C3a'%
System.err.println("文件下载结束！"); .V/TVz!b
} ^o?.Rph|i]
catch(Exception e){e.printStackTrace ();} 8{?Oi'-|0
} D*D83z OzN
&rw|fF|]
C:4h
//获得文件长度 Zls4@/\Q
public long getFileSize() <PV @JJ"
{ 3%<ia$
int nFileLength = -1; BvX!n"QIb
try{ +hXph
URL url = new URL(siteInfoBean.getSSiteURL()); B>?. Nr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z8'uZ#=Yw
httpConnection.setRequestProperty("User-Agent","NetFox"); m"U\;Mw?
S'3l<sY
/-BplU*"9
int responseCode=httpConnection.getResponseCode(); |_O; U=2
if(responseCode>=400) 1/le%}mK
{ mi97$Cr2
processErrorCode(responseCode); ,dh*GJ{5
return -2; //-2 represent access is error PjsQ+5[>
} !(SaE'
2d$hgR#v
ZfvFs
String sHeader; AFMAgf{bD
aYPzN<"%
EWqKd/
for(int i=1;;i++) hrcR"OZ~X
{ )QI]b4[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d>vGx
//Utility.log(in.readLine()); H,H'bd/
sHeader=httpConnection.getHeaderFieldKey(i); Q`19YX
if(sHeader!=null) eKStt|M'
{ NaVZ)
if(sHeader.equals("Content-Length")) L}:u9$w
{ 6x[gg !;85
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H3a}`3}U
break; {Ja#pt
} d(v )SS
} %X[|7D-
else _Dk;U*2
break; zD)2af
} b,318R8+G
} M}%0=VCY7
catch(IOException e){e.printStackTrace ();} 6"A|)fz
catch(Exception e){e.printStackTrace ();} 1YM04*H
YJ!6)d?C.
X.T.^}=
Utility.log(nFileLength); YToRG7X#
$,h*xb.
VnIJ$5Y
return nFileLength; q~l&EH0
} .}CPZ3y
i 3?zYaT
;'vY^I8-L
//保存下载信息（文件指针位置） 1Z`<HW"
private void write_nPos() ~Dkje
{ \".3x PkE
try{ a_x|PbD
output = new DataOutputStream(new FileOutputStream(tmpFile)); *y N,e.t
output.writeInt(nStartPos.length); 7 v`Y*D
for(int i=0;i<nStartPos.length;i++) 9*,5R,#
{ ld2\/9+n
// output.writeLong(nPos); 2I>CA[qp
output.writeLong(fileSplitterFetch.nStartPos); %W`pTvF
output.writeLong(fileSplitterFetch.nEndPos); DUW;G9LP$-
} `^w5/v#
output.close(); |5![k<o#
} g7d)YUc
catch(IOException e){e.printStackTrace ();} $>#PhOC
catch(Exception e){e.printStackTrace ();} ^QFjBQ-Hai
} t3bDi/m
YQYN.\
BHFWig*{
//读取保存的下载信息（文件指针位置） 7i/?+|
private void read_nPos() V?5_J%
{ //6m2a
try{ y4envjl0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r}vI#;&
int nCount = input.readInt(); .g4bV5ma3
nStartPos = new long[nCount]; f#^%\K:YYR
nEndPos = new long[nCount]; M{z+=c&w
for(int i=0;i<nStartPos.length;i++) *M KVm)Iv
{ YR[Ii?
nStartPos = input.readLong(); ,L_p"A
nEndPos = input.readLong(); q+LjWZ+O
} P7@qvg
input.close(); E[_Z%zd^
} qe\j$Cjy
catch(IOException e){e.printStackTrace ();} MK=:L
catch(Exception e){e.printStackTrace ();} 1S_KX.
} lYy0
]bS\*q0Zf(
!^\|r<2M
private void processErrorCode(int nErrorCode) 0>.'w\,87B
{ )EcF[aO
System.err.println("Error Code : " + nErrorCode); $'[( DwLS
} kv5D=0r
$RF"m"
LY^BkH'
//停止文件下载 , :kCt=4%
public void siteStop() [& hdyLt
{ TJO|{Lxm
bStop = true; Gzm[4|nO^
for(int i=0;i<nStartPos.length;i++) v_G4:tY
fileSplitterFetch.splitterStop(); gw5CU)r4$
S9xC> |<
r{Fu|aoa;5
} qLPI^g,
} } 10Dvt>+
//负责部分文件的抓取 wePMBL1P*
**FileSplitterFetch.java w|$;$a7)
*/ JXvHsCd?
package NetFox; &=s{ +0
r%xNfTa
TmUn/
import java.io.*; s]=kD
import java.net.*; r9u*c
Zl* HT%-5
b\;QR?16R
public class FileSplitterFetch extends Thread { d5u,x.R
U;{VL!
I:Z38xz-[
String sURL; //File URL j&#p&`B
long nStartPos; //File Snippet Start Position 4V[+6EV
long nEndPos; //File Snippet End Position '9RHwKu&s
int nThreadID; //Thread's ID K,^b=_]
boolean bDownOver = false; //Downing is over I@x*>
boolean bStop = false; //Stop identical xi|iV1A
FileAccessI fileAccessI = null; //File Access interface E%$FX'8&
LTJ|EXYA
l?#([(WM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'rd{fe_g!
{ 0 J ANj
this.sURL = sURL; V:l; 2rW
this.nStartPos = nStart; 0eb`9yM
this.nEndPos = nEnd; *Jp>)>
nThreadID = id; u#}zNz#C5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2>s:wABb /
} Ou,B3kuQ+
QMkLAZ
mWka!lT
public void run() mk[=3!J
{ O0~[]3Y[=
while(nStartPos < nEndPos && !bStop) Fv(zql
{ 7eu7ie6
EI/_=.d
;,9|;)U?u
try{ 0WYVt"|;}c
URL url = new URL(sURL); _YbHnb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hQX|wWh
httpConnection.setRequestProperty("User-Agent","NetFox"); v|n.AGn
String sProperty = "bytes="+nStartPos+"-"; OZ7MpQ
httpConnection.setRequestProperty("RANGE",sProperty); U[Z1@2zLx
Utility.log(sProperty); #<l;YT8
@n})oAC,
LeO5BmwHR
InputStream input = httpConnection.getInputStream(); }.e*=/"MB
//logResponseHead(httpConnection); T\2cAW5
@dO~0dF
Na[bCt
byte[] b = new byte[1024]; "esV#%:#J
int nRead; iUSs)[]H>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *UEo&B2+
{ hX[hR
nStartPos += fileAccessI.write(b,0,nRead); ]l&_Pv!!
//if(nThreadID == 1) YMm Fpy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =FdS'<GM
} S* <:He&1
oBIKtS*L
~9x$tb x-
Utility.log("Thread " + nThreadID + " is over!"); 6h;$^3x$
bDownOver = true; UG1^G07s
//nPos = fileAccessI.write (b,0,nRead); u*PN1E
} =1LrU$\
catch(Exception e){e.printStackTrace ();} F#W'>WBU
} ~EdmVEu
} +/AW6
4xg%OH
_.\p^ HM
//打印回应的头信息 -S9$C*t
public void logResponseHead(HttpURLConnection con) xNl_Q8Z?R^
{ UJlKw `4
for(int i=1;;i++) C+2*m=r
{ O(wt[AEA
String header=con.getHeaderFieldKey(i); E[e ''
if(header!=null) `)K1[&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LVO`+:
Utility.log(header+" : "+con.getHeaderField(header)); -w^E~J0*L
else l"O=xt`m{
break; ~hz]x^:
} .}]5y4UQ.
} iv3NmkP1
p6I@o7f
[ tmJ6^s
public void splitterStop() Jfo#IRC
{ *`mwm:4
bStop = true; R%54!f0 %
} Hz+edMUL
u9}=g%TV
* 496"kU
} $40tAes9
kg9ZSkJr
|P~TZ
/* Z>M0[DJ_
**FileAccess.java 8CwgV
*//文件访问(定位，写) \>M3E
package NetFox; :8\z 0
import java.io.*; 6fQQKM@a|
vvdC.4O
xUzfBn
public class FileAccessI implements Serializable{ lHr?sMt
E3sl"d;~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dN;C-XF3s
RandomAccessFile oSavedFile; YV 2T$#7u
long nPos; 6YYZ S2
-=2tKH`Q
k q_B5L?
public FileAccessI() throws IOException *|ubH?71%Y
{ B0nkHm.Sj
this("",0); :J}L| `U9
} ZVk_qA%
{N/(lB8
)Q&:$]
public FileAccessI(String sName,long nPos) throws IOException `A3"*,|z
{ U''/y\Z
oSavedFile = new RandomAccessFile(sName,"rw"); 6# ,2
this.nPos = nPos; T"XZ[q
oSavedFile.seek(nPos); h@@2vs2
} ebp18_a|
j^mAJ5
,o*x\jrGw
public synchronized int write(byte[] b,int nStart,int nLen) vRYfB{~
{ *Xn{{
int n = -1; *oKc4S+
try{ b~WiE?
oSavedFile.write(b,nStart,nLen); bK<'J=#1
n = nLen; MG<F.u
} o.*8$$
catch(IOException e) oj;Rh!O
{ q%2cx@c
e.printStackTrace (); ][I}yOD70
} R>BnUIu
`og 3P:y
v&(PM{3o
return n; ofC=S$wX
} -}AAA*P
OB.TAoH:
BRi\&&<4
} i<m1^a#C'
d *!)wt
>\+c@o[
/* wi|'pKG
**SiteInfoBean.java o $7:*jU
*/ )! Jo7SR
package NetFox; jgQn^
vR[XbsNM
\7n ;c
public class SiteInfoBean { 3WHj|ENW
x\z*iv
z/dpnGX
private String sSiteURL; //Site's URL (P%{Tab
private String sFilePath; //Saved File's Path 7k.=_Tl
private String sFileName; //Saved File's Name @eU;oRVc{
private int nSplitter; //Count of Splited Downloading File =]X_wA;%
]|KOc& y:I
$@QF<?i~
public SiteInfoBean() ue"?n2
{//nSplitter的缺省值为5 6q-X$
//default value of nSplitter is 5 o EXN$SIs
this("","","",5); 4! ]28[2B6
} ixm-wZI
}TI"j{(QJ
7:awUoV8f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2K[Y|.u8>q
{ U$-Gc[=|
sSiteURL= sURL; OHTJQ5%zL
sFilePath = sPath; JVy-Y
sFileName = sName; + :4 F@R
this.nSplitter = nSpiltter; W@Et
kG 7]<^Os3
<Ih)h$8`
} 9f1,E98w_
cih[A2lp
V9 Z
public String getSSiteURL() 82d~>i%T
{ 4}-{sS}MP
return sSiteURL; >d2U=Yk!
} k;BXt:jDq
r I)Y W0
'&v.h#<
public void setSSiteURL(String value) LGuK@^
{ $o}Ao@WkO
sSiteURL = value; <Cv6wC=
} p8gm=
g}\G@7Q
xb8S)zO]Q
public String getSFilePath() ]c/k%]o~
{ 1j4tR#L
return sFilePath; f0Wbc\L[
} SlK6KnX
EGJ d:>k
f0!i<9<
public void setSFilePath(String value) b&]_5 GGc
{ y(81| c#
sFilePath = value; f)'mpp^
} T)N_~f|
*BdKQ/Dk
9feVy\u
public String getSFileName() 7# !RX3
{ R"Ff(1m
return sFileName; GQ-fEIi{
} ^qR2!fwm<
)SjhOvm
NAg9EaWja{
public void setSFileName(String value) OS- Xh-:z
{ E!Ljq3iT`
sFileName = value; l4O&*,}l##
} E^K<b7
[}ayaXXQ5
u$M,&Om
public int getNSplitter() _dQg5CmlG
{ uE'O}Y95
return nSplitter; .dwy+BzS
} IoAG!cS
84U?\f@u
a*kvU"]
public void setNSplitter(int nCount) `AcUxnO
{ #];b+ T
nSplitter = nCount; Ga$J7R
} Vd&&GI(:?^
} gc6Zy|^V4`
4>t'4p6{
on^m2pQ *p
/* \>]C
**Utility.java 4it^-M
*/ w!kWG,{C
package NetFox; x9!3i{_
.91@T.
)hy(0 D
public class Utility { y&&%%3
chC= $(5t
ATG;*nIP
public Utility() |O';$a1S
{ >.=v*\P
o)]mJb~XG-
U0J_ 3W
} 1OI/,y8}
G(;hJ'LT
//线程睡眠 ^!v{ >3
public static void sleep(int nSecond) , RKl
{ BN>t"9XpW
try{ ABaK60.O[O
Thread.sleep(nSecond); f`W)Z$fN5
} )Vf!U"
catch(Exception e) =bHS@h8N<
{ Abc%VRsT
e.printStackTrace (); *}h#'+
} Q94Lq~?YF
} 7cQFH@SC
WcHL:38
//日志 JYw_Z*L=m
public static void log(String sMsg) `EdZ
{ fMm.V=/+
System.err.println(sMsg); +bDBc?HZ{$
} q@=3`yQ
@>Bgld&vl
M 8NWQ^Y
public static void log(int sMsg) DD fw& y
{ )R^&u`k
System.err.println(sMsg); =kP|TR!o-
} !)4'[5t"U
} J?%ecCN
,CxIA^
:\F1S:&P
/* Ly P Cc|
**TestMethod.java }h+{>{2j
*/ &WKAg:^k)
package NetFox; Dq[Z0"8
[pxC3{|d$
NCa3")k
public class TestMethod { rbl7-xhC7
nKnQ%R
O|AY2QH\
public TestMethod() =&t]R? F
{ ///xx/weblogic60b2_win.exe kyH0J[/n
try{ 9)*218.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7h#*djef
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eA_]%7+`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 85:KlBe%+
fileFetch.start(); AL{iQxQ6
} m*'hHt n
catch(Exception e){e.printStackTrace ();} }eAV8LU
nrV!<nNBk
puAjAvIax
} |)*9BN
{,B.OM)J
Wud-(19
public static void main(String[] args) q8!X^1F7
{ }2hU7YWt
new TestMethod(); \GPTGi5A
} l T#WM]
} 7/zaf
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