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)); $)!Z"2T
} (n\ cs$
for(int i=0;i<nEndPos.length-1;i++) ix;8S=eP~{
{ QR4o j
nEndPos = nStartPos[i+1]; ;nE}%lT
} 9 pn1d.
nEndPos[nEndPos.length-1] = nFileLength; ;f Gi5=-
} sTDBK!9I
} ~m7+^c@,
f&'md
ZUycJ-[
//启动子线程 z~qQ@u|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $.Ni'U
for(int i=0;i<nStartPos.length;i++) \=)h6AG
{ S%2qB;uw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mD!imq%=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9EEHLx"
nStartPos,nEndPos,i); `F#KXk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $)3/N&GXR
fileSplitterFetch.start(); .;'xm_Gw<
} ryN-d%t?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j*"s~8u4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <Vim\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4/b#$o<I?
nEndPos = " + nFileLength); IF=rD-x
// fileSplitterFetch[nPos.length-1].start(); ?4_;9MkN
^:BRbp37i
:.<&Y=^
//等待子线程结束 r"+ WUU
//int count = 0; S<TfvQ\,"@
//是否结束while循环 o9/P/PZ\X
boolean breakWhile = false; x{m)I<.:
(<12&=WxE
wZ^/-
while(!bStop) 99 ["I:
{ sb1/4u/W
write_nPos(); \ys3&<;b
Utility.sleep(500); W6pS.}
breakWhile = true; &IcDUr]L
A)xI.Q6
;(XSw%Y H
for(int i=0;i<nStartPos.length;i++) G 6][@q
{ z, OMR`W
if(!fileSplitterFetch.bDownOver) &5B+8>
{ Y !`H_Qo
breakWhile = false; Z1Ms~tch
break; eu#||
} @t_<oOI2
} \R~Lf+q
if(breakWhile) dgO2fI
break; !o`al` q'
vOqT Ld
j1BYSfX'
//count++; ?}W:DGudZ
//if(count>4) ?B-aj
// siteStop(); ,yB-jk?
} D!:Qy@Zw
<Sz9: hg-
(vY10W{
System.err.println("文件下载结束！"); LE7o[<>
} *@O;IiSE
catch(Exception e){e.printStackTrace ();} l!oU9
} b&LhydaJ
O".#B
U8moVj8w1
//获得文件长度 !XK p_v
public long getFileSize() #oHHKl=M
{ Wjj'yqBO^
int nFileLength = -1; .9`.\v6R
try{ il:+O08_
URL url = new URL(siteInfoBean.getSSiteURL()); W] RxRdY6[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +jHL==W&
httpConnection.setRequestProperty("User-Agent","NetFox"); U7{, *
>:Rc%ILym
b+w|3bQa
int responseCode=httpConnection.getResponseCode(); #KiRH* giU
if(responseCode>=400) ^fRA$t
{ U2G\GU1 X
processErrorCode(responseCode); ]Fa VKC~3
return -2; //-2 represent access is error GLEGyT?~
} {~Phc 2z
%R}}1
Rrsz{a
String sHeader; v=|ahsYC
rl!c\
,UY],;ib
for(int i=1;;i++) {uq
{ ."9v1kW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @*F NWT6
//Utility.log(in.readLine()); 1,Y-_e)
sHeader=httpConnection.getHeaderFieldKey(i); *ozeoX'5D
if(sHeader!=null) \vKMNk;kz
{ Zsaz#z|xW
if(sHeader.equals("Content-Length")) y+@7k3"
{ FLi)EgZXt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N{f RZN
break; {D$#m
} j:rGFd
} X5=Dc+
else u PjJ>v
break; l\a 0 k4
} *V5R[
} $5:j" )$,
catch(IOException e){e.printStackTrace ();} waldLb>7D
catch(Exception e){e.printStackTrace ();} mI@]{K}Q%
@MTm8E6au
ShFSBD\M#
Utility.log(nFileLength); GJU84Xn7
m%l\EE
G|v{[>tr
return nFileLength; 1%t9ic
} GVe[)R
X&pK#=
Z_Hc":4i
//保存下载信息（文件指针位置） b<NI6z8\
private void write_nPos() Bk*AO?3p
{ NO8)XJ3s
try{ >`SIB; &>j
output = new DataOutputStream(new FileOutputStream(tmpFile)); W/L~&.'
output.writeInt(nStartPos.length); +.:- :
for(int i=0;i<nStartPos.length;i++) |-%[Z
{ I4,C-D
// output.writeLong(nPos); L slI!.(
output.writeLong(fileSplitterFetch.nStartPos); :[?hU}9
output.writeLong(fileSplitterFetch.nEndPos); ?V3e;n
} QJjqtOf>
output.close(); h%9#~gJ})
} ZG"_M@S.
catch(IOException e){e.printStackTrace ();} 5L'X3g
catch(Exception e){e.printStackTrace ();} s,)Z8H
} .k|8nNj
ssUWr=mD
Cj#$WZga%
//读取保存的下载信息（文件指针位置） >$j?2,Za(V
private void read_nPos() !8(:G6Ne
{ |>Qj]
try{ %77v'Pz1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :q/%uca9
int nCount = input.readInt(); Q30AaG}f
nStartPos = new long[nCount]; ]yiwdQ
nEndPos = new long[nCount]; Ru9QQaHE
for(int i=0;i<nStartPos.length;i++) yY_Zq\
{ ZxFRE#y~2
nStartPos = input.readLong(); SfLZVB
nEndPos = input.readLong(); D,b'1=
} n** W
input.close(); dZK/v
} -fKo~\Pr
catch(IOException e){e.printStackTrace ();} T)?:q
catch(Exception e){e.printStackTrace ();} h fZY5+Z<
} la+RK
P|%uB'|H
<[Oe.0SGu
private void processErrorCode(int nErrorCode) ia6%>^
{ 6}4?,r
System.err.println("Error Code : " + nErrorCode); ?5-Y'(r
} ]-]K4*{
H3CG'?{ _
"NWILZwEV
//停止文件下载 v"ZNS
public void siteStop() ^,O%E;g^#
{ rO4R6A
bStop = true; wX<w)@
for(int i=0;i<nStartPos.length;i++) [}:;B$,
fileSplitterFetch.splitterStop(); DXA<m2&64N
Z$jqB~=^e
5,dKha
} c[VVCN8dA
} 6)=`&>9
//负责部分文件的抓取 +guCTGD:
**FileSplitterFetch.java 3ScOJo
*/ ^IW5c>;|
package NetFox; r)<c ~\0 7
gOb"-;Zw
M]|tXo$?
import java.io.*; x Zp`
import java.net.*; |xYr0C[Pq
k4T`{s}e
HE!"3S2S&+
public class FileSplitterFetch extends Thread { ,i RUR8
qh9d.Q+n
zH|YVg
String sURL; //File URL D*=.;Rq
long nStartPos; //File Snippet Start Position nIZ;N!r=i
long nEndPos; //File Snippet End Position V_\9t8
int nThreadID; //Thread's ID ~cr##Ff5
boolean bDownOver = false; //Downing is over 2P,%}Ms
boolean bStop = false; //Stop identical d!57`bVOd
FileAccessI fileAccessI = null; //File Access interface L0\~K~q
+-X 68`
?i{/iH~Sf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LO;7NK
{ Uv)B
this.sURL = sURL; E4N/or
this.nStartPos = nStart; 1u8 k}
this.nEndPos = nEnd; =0t<:-?.-
nThreadID = id; :_8Nf1B+T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t1`.M$
} Talmc|h
O,PTY^
+-r ~-bs
public void run() gCV+amP
{ eC{St0
while(nStartPos < nEndPos && !bStop) 6nA/LW\x
{ yQcIfl]f
N&yr?b'!-*
1,7
try{ 8-B6D~i
URL url = new URL(sURL); 70<{tjyc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "l 8YD&q
httpConnection.setRequestProperty("User-Agent","NetFox"); "T@9#7Obu
String sProperty = "bytes="+nStartPos+"-"; 'pnOHT
httpConnection.setRequestProperty("RANGE",sProperty); K+\2cf?bU
Utility.log(sProperty); dL]wu!wE
eC3 ~|G_O
LzTdi%u$0|
InputStream input = httpConnection.getInputStream(); QXu[<V
//logResponseHead(httpConnection); !$NQF/Ol
WJJmM*>JW
Z'UhJuD5
byte[] b = new byte[1024]; }Uu#N H
int nRead; hnimd~E52k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g43(N!@g
{ &gF9VY
nStartPos += fileAccessI.write(b,0,nRead); [*J?TNk
//if(nThreadID == 1) :85QwN]\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TKp2C5bX
} '':MhRb
$[g#P^
JU#m?4g
Utility.log("Thread " + nThreadID + " is over!"); I5@8=rFk
bDownOver = true; B.C:06E5
//nPos = fileAccessI.write (b,0,nRead); cd|/4L6
} IISdC(5
catch(Exception e){e.printStackTrace ();} Vx{
} WMa`!Q
} ||L^yI~_d
&5[B\yv
nAC>']K4$
//打印回应的头信息 mp)+wZAN&
public void logResponseHead(HttpURLConnection con) v\@pZw=x
{ dT0>\9ZNr
for(int i=1;;i++) vb| d
{ D\Y,2!I
String header=con.getHeaderFieldKey(i); S5kD|kJ
if(header!=null) LzxO=+=9!q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8|(],NyEJ
Utility.log(header+" : "+con.getHeaderField(header)); ~{GTL_w
else :p%#U$S4
break; +z[+kir
} D |=L)\
} UhJ{MUH`
SOZs!9oi
)PkW,214#
public void splitterStop() @?jtB
{ )FSEHQ
bStop = true; t,n2N13
} XG!6[o;
c39j|/!;Y
l<p<\,nV$
} ~MP |L?my
S.{
,!,tU7-H
/* Sl-9im1
**FileAccess.java r\cY R}v
*//文件访问(定位，写) -k@1#c+z
package NetFox; 6$0<&')Yb
import java.io.*; 5dhy80|g]
`!spi=f
rW090Py
public class FileAccessI implements Serializable{ [?hvx}
xXc>YTK'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rHM^_sYRb
RandomAccessFile oSavedFile; |N^"?bSt
long nPos; SQhVdYU1'
<f`n[QD2z
BU4IN$d0Po
public FileAccessI() throws IOException g$jTP#%b
{ &AOGg\
this("",0); [& Z- *a
} ;c>"gW8
{%CW!Rc
<R+?>kz6
public FileAccessI(String sName,long nPos) throws IOException Q"B8l[
{ wViTMlq
oSavedFile = new RandomAccessFile(sName,"rw"); nu7 R
this.nPos = nPos; FZO&r60$E
oSavedFile.seek(nPos); N$=9R
} t$%<eF@w
u z7|!G!43
Lui6;NY
public synchronized int write(byte[] b,int nStart,int nLen) 1Ml<>
{ +uSp3gE"
int n = -1; CQNMCYjg(R
try{ <tBT?#C9+
oSavedFile.write(b,nStart,nLen); 9 " t;6
n = nLen; z@,(^~C_
} Z$g'h1,zW
catch(IOException e) ?d3FR!
{ u<uc"KY=
e.printStackTrace (); \Cu=Le^
} i+qg*o$
05k'TqT{c
>\^oCbqF}~
return n; Pj]^p{>
} (3mL!1\
p<(a);<L
@'}2xw[eU
} ]7cciob
.%{B=_7
Y,v9o
/* S*=^I2;
**SiteInfoBean.java LdH1sHy*d`
*/ 3o[(pfcU
package NetFox; >qB`03>
?g{[U0)
pP1DR'
public class SiteInfoBean { ?wPTe^Qtv
i8k} B o
C5-u86F
private String sSiteURL; //Site's URL \t1#5
private String sFilePath; //Saved File's Path n]Yz<#
private String sFileName; //Saved File's Name eu"m0Q
private int nSplitter; //Count of Splited Downloading File oNe:<YT
iB(?}SaAZ
w-ald?`
public SiteInfoBean() fcEm:jEZ*
{//nSplitter的缺省值为5 &WBpd}|+Y
//default value of nSplitter is 5 &! h~UZ
this("","","",5); )L6 it
} ..E_M$}
9ybR+dGm+
Z(c SM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PdVx&BL*
{ ?i0+h7=6
sSiteURL= sURL; :t!J 9
sFilePath = sPath; PvV\b<Pe+
sFileName = sName; rgCC3TX
this.nSplitter = nSpiltter; /klo),|&
~y"R{-%uS
?]Hs~n-
} (^FMm1@T
[[^r;XKQ
0@b<?Ms9
public String getSSiteURL() $peL1'Evo
{ XrTc5V
return sSiteURL; h ChO
} 9C,gJp}P
NpZ'pBl
9ThsR&h3
public void setSSiteURL(String value) QxE%C
{ guYP|
sSiteURL = value; -M6vg4gf
} EiC["M'}
g]HxPq+O
A\rY~$Vr
public String getSFilePath() *!y04'p`<
{ N?{Zrff2"O
return sFilePath; vb0Ca+}}
} y~#5!:Be
<ZZfN@6
SGZYDxFC@
public void setSFilePath(String value) c/bT5TIEWs
{ xC _3&.
sFilePath = value; |>j^$^l~
} [7`S`\_NK
uv$5MwKU
/rD9)
public String getSFileName() OI)k0t^;D
{ wjX0r7^@
return sFileName; n~`jUML2d
} 8cY5:plK
qfFa" a
!?i9fYu
public void setSFileName(String value) ;MYK TE>m
{ jK6dI 7h
sFileName = value; }W " i{s/
} r\b$/:y<e
]OKKR/:
U/U_q-z]
public int getNSplitter() [C 7X#|
{ DP*V|)
return nSplitter; ,bzgjw+R5
} Q"pZPpl&
k~<ORnda
!_o1;GzK
public void setNSplitter(int nCount) QB*AQ5-
{ P1TTaYu
nSplitter = nCount; q,Nqv[va
} !C' Y 7
} }236{)DuN
2+(SR.oGq
[F *hjGLc}
/* "wV7PSbM
**Utility.java 8.`5"9Vh
*/ 3=L5Y/
package NetFox; SV2\vby}C
LGRhCOP:
C0e oV}
public class Utility { y3'K+?4
viS7+E|O
ir)~T0
public Utility() ap|V}jC
{ >?X(,c
x2]chN
.a]av
} _32 o7}!x
L|2WTyMU
//线程睡眠 <M3&\
public static void sleep(int nSecond) &ujq6~#
{ pvqbk2BO
try{ ?O e,
Thread.sleep(nSecond); ~ln96*)M;
} ^MZ9Zu_
catch(Exception e) g>f_'7F&
{ +-:G+9L@
e.printStackTrace (); +u7nx
} FVHR
} a*@4W3;7
b;(BMO,(
//日志 G?yG|5.pU
public static void log(String sMsg) !='&#@7u
{ ATU]KL!{
System.err.println(sMsg); 0(!=N1l
} gtb,}T=1
F, p~O{ Q
_/[(&}M
public static void log(int sMsg) }W R?n
{ _Nq7_iT0
System.err.println(sMsg); iX'#~eK*<
} 3HmJixy
} RV+0C&0ff
7(= 09z
6/thhP3`-
/* SA16Ng
**TestMethod.java Z\M8DZW8Y
*/ A4|a{\|$
package NetFox; gkDlh{
`~3y[j]kO
! .|\}=[e
public class TestMethod { ZiOL7#QWX
d>NM4n[h8
8L*P!j9`EY
public TestMethod() pO_L,~<
{ ///xx/weblogic60b2_win.exe C_DXg-a2lu
try{ S+(-k0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]p2M!N,?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {m+(j (6-
SiteFileFetch fileFetch = new SiteFileFetch(bean); &ahZ_9Q
fileFetch.start(); ^.@BD4/RPt
} 9Iod[ x
catch(Exception e){e.printStackTrace ();} (AnM_s
$R[ggH&
]2P*Z6Az
} &qP&=( $
36U zfBa
2,X~a;+
public static void main(String[] args) #A2)]XvY
{ Xr@]7: ,
new TestMethod(); u/BCl!`
} zLxO\R!d
} @dzO{)
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