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)); spt6]"Ni
} rg^'S1x|
for(int i=0;i<nEndPos.length-1;i++) e" St_z(
{ :A/d to
nEndPos = nStartPos[i+1]; 5H*\t 7
} 8_{X1bj
nEndPos[nEndPos.length-1] = nFileLength; Z'"tB/=W
} mIK7p6
} L*YynF
a!=D[Gz*5
BO;6 u^[
//启动子线程 \ExMk<y_&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r"P|dlV-
for(int i=0;i<nStartPos.length;i++) eAE`#t
{ 7S}_F^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R}O_[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $<}$DH_Y
nStartPos,nEndPos,i); '.:z&gSqx0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P-?0zF/T$
fileSplitterFetch.start(); &J+CSv,39
} wne,e's}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LDPUD'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `aciXlqIF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Lm%:K]X
nEndPos = " + nFileLength); '<"s \,
// fileSplitterFetch[nPos.length-1].start(); G3Z)Z)N
`@`CG[-9
3kybLOG
//等待子线程结束 )h7<?@wv&
//int count = 0; e)d`pQ6
//是否结束while循环 <J)]mh dm
boolean breakWhile = false; ?l9XAWt\
D]zwl@sRX:
8X[:j&@
while(!bStop) U/!TKic+
{ 5>[u `
write_nPos(); ,J+}rPe"sf
Utility.sleep(500); qm/)ku0
breakWhile = true; ,U2*FZ["
'Gj3:-xqL
9Z4nAc
for(int i=0;i<nStartPos.length;i++) M/b Sud?@%
{ .(K)?r-g5
if(!fileSplitterFetch.bDownOver) ~E17L]ete
{ Y3Yz)T}UkS
breakWhile = false; yDzc<p\`
break; LRL,m_gt
} }\B><E{G
} "&Y`+0S8
if(breakWhile) k>;`FFQU>
break; HiZ*+T.B
G?O1>?4C
6^]+[q}3
//count++; !|^|,"A)
//if(count>4) b3=rG(0f
// siteStop(); 0XE4<U
} eA2@Nkw~)
ofm#'7P 0
-|$@-fY;
System.err.println("文件下载结束！"); rC5 p-B%
} ,E S0NA
catch(Exception e){e.printStackTrace ();} ssfr}fzH
} KcWN,!G
l+KY)6o
| )K8N<n
//获得文件长度 V%rzk*LA
public long getFileSize() TM%|'^)
{ OP[@k
int nFileLength = -1; )_YX DU
try{ o#3ly-ht
URL url = new URL(siteInfoBean.getSSiteURL()); ]_f_w9]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d,k!qjf=r
httpConnection.setRequestProperty("User-Agent","NetFox"); T(id^w
E(>=rD/+
P3x8UR=fS
int responseCode=httpConnection.getResponseCode(); (7wc*#}
if(responseCode>=400) 5_GYrR2
{ M\uiq38
processErrorCode(responseCode); {$0mwAOH "
return -2; //-2 represent access is error DX#Nf""Pw
} , qMzWa
slCx w$
}Y12
String sHeader; n(1l}TJy
@LF,O}[2J
D+lAhEN
for(int i=1;;i++) .s?L^Z^
{ #NEE7'&S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZgTW.<.%2
//Utility.log(in.readLine()); {'7B6
sHeader=httpConnection.getHeaderFieldKey(i); - YEZ]:"
if(sHeader!=null) /6)<}#
{ *& BQTZ6
if(sHeader.equals("Content-Length")) xQ f*
{ BtkOnbz8X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3#3n!(
break; bQgc8/
} t%d Z-Ym
} 0yk]o5a++
else T6\[iJI|
break; (nQ^
} p$S*dr
} 94'&b=5+
catch(IOException e){e.printStackTrace ();} `KZm0d{H
catch(Exception e){e.printStackTrace ();} 5'OrHk;u
G30-^Tr
8I=2lK
Utility.log(nFileLength); Ouk^O}W6
q}3`|'3
rDdoOb]B
return nFileLength; is?{MJZ_
} ?>7[7(|
\"7*{L:
R$R*'l
//保存下载信息（文件指针位置） !z\h|wU+
private void write_nPos() \1k79c
{ Hus)c3Ty7
try{ {5Q!Y&N.%
output = new DataOutputStream(new FileOutputStream(tmpFile)); E^B'4
output.writeInt(nStartPos.length); 8?xE6
for(int i=0;i<nStartPos.length;i++) /:cd\A}
{ ju8>:y8
// output.writeLong(nPos); 1KU! tL
output.writeLong(fileSplitterFetch.nStartPos); M H|Og84
output.writeLong(fileSplitterFetch.nEndPos); #|uCgdi
} )HEa<P^kJl
output.close(); [:7'?$
} #]\Uk,mhZB
catch(IOException e){e.printStackTrace ();} ^ gdaa>L
catch(Exception e){e.printStackTrace ();} ) ;EBz
} tj'\tW+s'
&h}#HS>l
iDpSj!x/_
//读取保存的下载信息（文件指针位置） _P!m%34|
private void read_nPos() Sj3+l7S?
{ p?02C#p
try{ l[dK[4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wo3d#=
int nCount = input.readInt(); #$.;'#u'so
nStartPos = new long[nCount]; &sl0W-;0
nEndPos = new long[nCount]; CXH&U@57{
for(int i=0;i<nStartPos.length;i++) p/ ,=OaVU
{ ?e%ZOI
nStartPos = input.readLong(); lt/1f{v[:
nEndPos = input.readLong(); l|u>Tb|V
} !Lu2
input.close(); ]}V<*f
} V.U| #n5
catch(IOException e){e.printStackTrace ();} ncaT?~u j
catch(Exception e){e.printStackTrace ();} 0-B5`=yU
} 4VHn \
R!HXhQ
W~)}xy
private void processErrorCode(int nErrorCode) 21n?=[
{ v_yw@
System.err.println("Error Code : " + nErrorCode); t$`r4Lb9/
} @="Pn5<]C
F/]2G^-
\__i
//停止文件下载 kpuz]a7pK
public void siteStop() 1s\Wtw:
{ zOJ%}
bStop = true; )7hqJa-V
for(int i=0;i<nStartPos.length;i++) \<bx[,?
fileSplitterFetch.splitterStop(); ."g`3tVK
B.=FSow
.7J#_*NV
} pd?Mf=>#
} G0Iw-vf
//负责部分文件的抓取 M*0]ai|;
**FileSplitterFetch.java &s(^@OayE
*/ IYv`IS"
package NetFox; 9gW|}&-
_T60;ZI+^
'B|JAi?
import java.io.*; 6%'QjwM_
import java.net.*; MxKS4k
/l3V3B7
GblA9F7
public class FileSplitterFetch extends Thread { hDDn,uzpd
dRYqr}!%n
fuW\bo3
String sURL; //File URL 3<Lx&p~%T
long nStartPos; //File Snippet Start Position 6XxvvMA97
long nEndPos; //File Snippet End Position y RqL9t
int nThreadID; //Thread's ID RbB.q p
boolean bDownOver = false; //Downing is over _;"il%l=1
boolean bStop = false; //Stop identical #mxPw
FileAccessI fileAccessI = null; //File Access interface q])K,)
}{Pp]*I<A
-OV&Md:~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ROI7eU
{ ijv(9mR
this.sURL = sURL; xo^b&ktQd
this.nStartPos = nStart; 2DA]i5
this.nEndPos = nEnd; RHW]Z Pr<
nThreadID = id; AI2)g1m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z^B,:5Tt
} \ #F
+Ze}B*0
hPkp;a #
public void run() =IZT(8
{ iT+8|Yia
while(nStartPos < nEndPos && !bStop) #\{l"-
{ E_rI?t^
gT.sjd
vO^m;['
try{ )_90UwWpj
URL url = new URL(sURL); zpn9,,~u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,>a&"V^k
httpConnection.setRequestProperty("User-Agent","NetFox"); fgTg7 m
String sProperty = "bytes="+nStartPos+"-"; ^e,.
httpConnection.setRequestProperty("RANGE",sProperty); RNk\.}m
Utility.log(sProperty); kt#fMd$
u[;\y|75
Q-oktRK
InputStream input = httpConnection.getInputStream(); xK[ou'
//logResponseHead(httpConnection); Oi.C(@^(
tAd%#:K
,L2ZinU:
byte[] b = new byte[1024]; l\H=m3Bg
int nRead; d0!5j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Pc;5 o0C
{ 8Al{+gx@?
nStartPos += fileAccessI.write(b,0,nRead); v4TQX<0s
//if(nThreadID == 1) ktXM|#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?FZ HrA
} l'rja.\
P= BZ+6DS
EU 6oQ
Utility.log("Thread " + nThreadID + " is over!"); U+jOTq8M
bDownOver = true; e*kpdS~U&
//nPos = fileAccessI.write (b,0,nRead); &J]K3w1p
} Pbn*_/H
catch(Exception e){e.printStackTrace ();} \!X8
} VBlYvZ;$*
} z|J_b"u4
HVCe;eI
?=msH=N<l
//打印回应的头信息 eb{nWP
public void logResponseHead(HttpURLConnection con) DCO\c9
{ `g?Negt\v
for(int i=1;;i++) W+c<2?d:
{ xj)F55e?
String header=con.getHeaderFieldKey(i); HyQJXw?A:
if(header!=null) O/(`S<iip
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }"H,h)T
Utility.log(header+" : "+con.getHeaderField(header)); R%WCH?B<}
else yxQ1`'[CR
break; hh%-(HaLX3
} B"w?;EeV.
} a5^]20Fa
sE<V5`Z=
7aRi5
public void splitterStop() !*&V-4
{ ?p{Nwl#
bStop = true; y14;%aQN
} 6Pnjmw.HV
1-uxC^u?|#
76Cl\rV
} 7F7{)L
J4C.+![!Ah
W(Fv l
/* Rok7n1gW
**FileAccess.java B]wk+8SMY.
*//文件访问(定位，写) H2\;%K 2
package NetFox; | j`@eF/"
import java.io.*; 1=c\Rr9]
&{hL&BLr
mDABH@R
public class FileAccessI implements Serializable{ #G|RnV%t$~
[b%D3-}'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >8^ $ [}w
RandomAccessFile oSavedFile; X7MM2V
long nPos; bo>*fNqAIy
{6|G@""O
65P0,b6"OT
public FileAccessI() throws IOException nnEgx;Nl0
{ D/xbF`
this("",0); 2WL|wwA
} ZF8 yw(z
7IH@oMvE
(N6i4 g6
public FileAccessI(String sName,long nPos) throws IOException V7Lxfoa4
{ 7kLz[N6Ll
oSavedFile = new RandomAccessFile(sName,"rw"); CyFrb`%
this.nPos = nPos; Qj.#)R
oSavedFile.seek(nPos); %nZo4hnr$r
} 6I4\q.^qw
]@c+]{
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public synchronized int write(byte[] b,int nStart,int nLen) GW@;}m(
{ YUD`!C
int n = -1; BO;tCEV?
try{ D,*3w'X!K
oSavedFile.write(b,nStart,nLen); rQs)O<jl
n = nLen; 8 +/rlHp
} [A~xy'T
catch(IOException e) iRbT/cc{
{ -#[a7',Z;
e.printStackTrace (); 6dt]`zv/
} 9';JXf$
FaSf7D`C
$y&E(J
return n; BwGfTua
} (O?.)jEW(.
d#Y^>"|$.
rSk>
} 29"'K.r
W~;`WR;.
Lc,Pom
/* ~9]hV7y5C
**SiteInfoBean.java w~A{(- dx
*/ hGe/;@%
package NetFox; dJoaCf`w
~s*)f.l
X6X $Pve
public class SiteInfoBean { 5"@*?X K^
0B/,/KX
Su7?;Oh/yI
private String sSiteURL; //Site's URL ;>yxNGV`
private String sFilePath; //Saved File's Path &*,#5.
private String sFileName; //Saved File's Name hoUD;3
private int nSplitter; //Count of Splited Downloading File i2Qz4 $z
YMcD|Kbp
Y|f[bw
public SiteInfoBean() H>IMf/%5N-
{//nSplitter的缺省值为5 ay ;S4c/_
//default value of nSplitter is 5 u@UMP@"#
this("","","",5); c /HHy,
} /GN<\_o=q
SI-qC
)e+>w=t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^z IW+:
{ F=e8IUr
sSiteURL= sURL; ci.+pF
sFilePath = sPath; $?Hu#Kn,(
sFileName = sName; 2B[X,rL.pX
this.nSplitter = nSpiltter; jyUjlYAAv`
ox~o J|@
3g,`.I_
} dI(@ZV{
:Zbg9`d*
2d #1=+V
public String getSSiteURL() KNvZm;Q6
{ gnOt+W8
return sSiteURL; 8,4"uuI
} ]Idk:et
4{U T!WIi
?%-DfCS
public void setSSiteURL(String value) x7&B$.>3
{ @s;;O\
sSiteURL = value; H?vdr:WlTN
} FEz-+X<q2
3*"WG O5
{0wIR_dGX
public String getSFilePath() t;}|tgC
{ e "4 ''/
return sFilePath; \5:i;AE
} 5h=}j
%~H-)_d20
DFB@O|JL
public void setSFilePath(String value) a`E#F]Z
{ :Uzm
sFilePath = value; M#4pE_G
} 30#s aGV
/tx]5`#@7]
;~)5s'
public String getSFileName() y|i,|
{ ?r "{}%
return sFileName; \O3m9,a
} A5I)^B<(
rxvx
{l1.2!
public void setSFileName(String value) ifMRryN4
{ wo;~7K
sFileName = value; 7Jyy z,!5
} en4k/w_
a od-3"7[
zII|9y
public int getNSplitter() )hn6sXo+
{ u^+7hkk
return nSplitter; DZ'P@f)]
} {0Yf]FQb-a
,Bi.1 %$
dC3o9
public void setNSplitter(int nCount) Z*]9E^
{ 8yR.uMI$/
nSplitter = nCount; <sGVR5NR
} Db}j?ik/
} ;40/yl3r3[
Fx_z6a
sk<3`x+
/* |PCm01NU!
**Utility.java 0y'H~(
*/ :1.L}4"gg
package NetFox; shy-Gu&
mA}TJz
sQHv%]s 0
public class Utility { pSH=%u>
Eak$u>Fd8c
hB]Np1('
public Utility() D(@S+r_ota
{ hc(#{]].
KEo,m
ios&n)W&
} WtsFz*`)y
*MFIV02[N
//线程睡眠 7?!d^$B
public static void sleep(int nSecond) ed{ -/l~j
{ z [}v{
try{ .]Y$o^mf
Thread.sleep(nSecond); .,|G7DGH]
} m/@wh a
catch(Exception e) k<nZ+! M
{ ,GhS[VJjR
e.printStackTrace (); ,hm\
} YlJ@XpKM
} lV3x*4O=
Fh&G;aEq
//日志 Wa>}wA=v
public static void log(String sMsg) lwxaMjaL4K
{ d`=MgHz
System.err.println(sMsg); FJGlP&v<
} `!3SF|x&
@|Cz-J;D
hn7# L
public static void log(int sMsg) >W=,j)MA
{ ;LKkbT 5
System.err.println(sMsg); L^/5ux
} e9Wa<i8
} )Yh+c=6 ?
gS!:+G%
t9GR69v:?
/* z3{G9Np
**TestMethod.java n:I,PS0H<
*/ c)6m$5]
package NetFox; fZGX}T<)p-
.ljnDL/
pGP7nw_g
public class TestMethod { jh?H.;**
Y#ap*
:DK {Vg6
public TestMethod() 8?B!2
{ ///xx/weblogic60b2_win.exe Ke;E1S-~
try{ "b~+;<}Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ('4_ xOb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [NjXO`5#]
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^ glri$m
fileFetch.start(); %vn"{3y>rF
} T#T*Zw"+
catch(Exception e){e.printStackTrace ();} j1Y~_
4B8oO
XFVE>/H
} fh&nu"&
v|)4ocFK
1W c=5!
public static void main(String[] args) nK1Slg#U
{ >mbHy<<
new TestMethod(); 9d0@wq.
} =g7x' kN
} nSDMOyj+
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