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)); V 2Xv)
} Zl[EpXlZ
for(int i=0;i<nEndPos.length-1;i++) f0eQq;D$K
{ PE.UNo>o
nEndPos = nStartPos[i+1]; tOXyle~C
} Ew4D';&;
nEndPos[nEndPos.length-1] = nFileLength; 9z?c0W5x
} e"1mdw"
} UhR^Y{W5
wsdZwik
sudh=_+>
//启动子线程 &$ }6:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eP (*.
for(int i=0;i<nStartPos.length;i++) q AVypP?J
{ 8K^#$,.."
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xlcCL?qQj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -qpvVLR,
nStartPos,nEndPos,i); ;0Uat
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N[9o6Nl|a
fileSplitterFetch.start(); Ri"rT] '
} j7d^ga-`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xJ#O|7N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xTk6q*NvT^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]G&[P8hzB
nEndPos = " + nFileLength); 'h ?
// fileSplitterFetch[nPos.length-1].start(); b+Sj\3fX
ql%K+4@
i=5!taxu}E
//等待子线程结束 eG+$~\%Fub
//int count = 0; O-0 5.
//是否结束while循环 S#CaJ}M
boolean breakWhile = false; ^?|4<Rm
BgN^].z&
t(<k4ji,
while(!bStop) /?BTET
{ LQqba4$
write_nPos(); irh Z
Utility.sleep(500); 2K3j3|T
breakWhile = true; nUs=PD3)
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m5/]+xdNX
for(int i=0;i<nStartPos.length;i++) [4EIy"
{ f7zB_hVDmE
if(!fileSplitterFetch.bDownOver) V(XU^}b#
{ g[y&GCKY!=
breakWhile = false; Ce//;Op
break; Nnn~7
} ,nog6\
} bs}SFTL
if(breakWhile) Rhlm
break; U4Zx1ieCKH
HI1|~hOb'
MF$Dx| Tcj
//count++; 'oGMr=gp<&
//if(count>4) EWl9rF@I
// siteStop(); ">B&dNrt
} |+~P; fG
O*2{V]Y @
iYa)*,
System.err.println("文件下载结束！"); Lcg1X3$G
} w@mCQ$
catch(Exception e){e.printStackTrace ();} F" G+/c/L
} BGNZE{K4"
!9qw
o8g]ho
//获得文件长度 ]}S9KP
public long getFileSize() "1dpv\
{ &~<i" W
int nFileLength = -1; +pUYFDwFx
try{ ^tyqc8&
URL url = new URL(siteInfoBean.getSSiteURL()); H[R6 ?H@$F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dtQ3iuV %
httpConnection.setRequestProperty("User-Agent","NetFox"); mE+=H]`.p
PMiu "
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int responseCode=httpConnection.getResponseCode(); $v8T%'p+
if(responseCode>=400) 3]NKAPY
{ ]Gj%-5G
processErrorCode(responseCode); b;`MHEzw&q
return -2; //-2 represent access is error }WR@%)7ay
} NUBzc'qb
1@-l@ P
?iaO+G&|
String sHeader; rIyIZWkI
t[({KbIy
0p,_?3nX
for(int i=1;;i++) Nog{w
{ JBV 06T_4o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G]-\$>5R
//Utility.log(in.readLine()); # b3 14
sHeader=httpConnection.getHeaderFieldKey(i); ieOw&
if(sHeader!=null) fX LsLh+~D
{ aTaL|&(
if(sHeader.equals("Content-Length")) }PMlG
{ IQ JFL +f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GB*^?Ii
break; kT^`j^Jr
} qP/McH?
} AAi4} 8+\
else %@I= $8j
break; b^~4k; <
} p%Ns f[1>
} wLq#,X>%B
catch(IOException e){e.printStackTrace ();} >'3nsR
catch(Exception e){e.printStackTrace ();} [MAvU?;
vA?3kfL|#
}y|_v^
Utility.log(nFileLength); O/l/$pe
h?QGJ^#8
#E/|WT
return nFileLength; +D h?MQt?
} =4/K#cQ
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9:!V":8q
//保存下载信息（文件指针位置） >(gbUW
private void write_nPos() %zjyZ{=
{ t4zKI~cO
try{ PTF|"^k+
output = new DataOutputStream(new FileOutputStream(tmpFile)); {o%OG/!1
output.writeInt(nStartPos.length); R|\kk?,u
for(int i=0;i<nStartPos.length;i++) OQ3IkE`G
{ b\SB
// output.writeLong(nPos); oPxh+|0?
output.writeLong(fileSplitterFetch.nStartPos); I_`$$-|
output.writeLong(fileSplitterFetch.nEndPos); 2N&S__
} )uCa]IR
output.close(); /7R0w
} 9 b&HqkXX
catch(IOException e){e.printStackTrace ();} W 6R/{H
catch(Exception e){e.printStackTrace ();} VkC1\L6
} ;3=RM\
A2nL=9~
FdxV#.BE
//读取保存的下载信息（文件指针位置） bL%-9BG
private void read_nPos() "6WE6zq
{ &7w*=f8I
try{ r#mH[|@W~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G'iE`4`2
int nCount = input.readInt(); #!jwn^yq
nStartPos = new long[nCount]; a/~1CrYr
nEndPos = new long[nCount]; _o6Zj1p
for(int i=0;i<nStartPos.length;i++) ib(4Y%U6~
{ aslb^
nStartPos = input.readLong(); ~kZ?e1H
nEndPos = input.readLong(); a^)@}4
} VpxsgCS
input.close(); c*V/2" 5
} Q/l388'
catch(IOException e){e.printStackTrace ();} 239gpf]}
catch(Exception e){e.printStackTrace ();} d?[8VfAnh
} )%I62<N,z
1[(/{CClB
\2[
private void processErrorCode(int nErrorCode) _WBWFGj
{ 0w".o!2\U{
System.err.println("Error Code : " + nErrorCode); h(FFG%H(
} Z"9D1Uk
j-/F*P
YZc{\~d
//停止文件下载 ^B'N\[
public void siteStop() $btk48a7
{ ^Zq3K
bStop = true; LHusy;<E[
for(int i=0;i<nStartPos.length;i++) U1pwk[
fileSplitterFetch.splitterStop(); Wl{}>F`W[
sWMY Lo
: UDh{GQ*
} _3m\r*(vmQ
} 'q{d? K
//负责部分文件的抓取 _^NL{R/
**FileSplitterFetch.java `6Yk-5
*/ q[~+Zm
package NetFox; 8sU}[HH*1
TxmKmZ u
RxGZ#!j/
import java.io.*; P?M WT]fY
import java.net.*; Hg+bmwM
7HQ|3rt
10..<v7
public class FileSplitterFetch extends Thread { R5rCCp
kO'NT:
=BgQSs/^c
String sURL; //File URL tZN'OoZ
long nStartPos; //File Snippet Start Position Wo/LrCg
long nEndPos; //File Snippet End Position aq]bF%7
int nThreadID; //Thread's ID ,M9Hdm
boolean bDownOver = false; //Downing is over Y'x+!&H
boolean bStop = false; //Stop identical g:[yA{Eh
FileAccessI fileAccessI = null; //File Access interface T3/Gl6f
0t0m?rVW
8'VcaU7Nh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a>)|SfsE
{ /~_,p,:aP
this.sURL = sURL; `j(-y`fo
this.nStartPos = nStart; uVLKR PY
this.nEndPos = nEnd; 6cTd SE
nThreadID = id; Eh.NJI(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @l@erCw@
} %g=SkQ&d
F44KbUH
u\}"l2 r
public void run() Xs$UpQo
{ 0)9'x)l:
while(nStartPos < nEndPos && !bStop) ]t.6bb4
{ 8i?:aN[.1b
Aw7_diK^
u*<knZ~ty
try{ J+f*D+x1
URL url = new URL(sURL); 7\Wq:<JL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )\l(h%s[I
httpConnection.setRequestProperty("User-Agent","NetFox"); -i"?2gK
String sProperty = "bytes="+nStartPos+"-"; ,&rHBNS
httpConnection.setRequestProperty("RANGE",sProperty); rL<a^/b/=
Utility.log(sProperty); bjB4
:eW`El
.#}`r`/
InputStream input = httpConnection.getInputStream(); S2"HE`
//logResponseHead(httpConnection); vUgMfy&
yq\p%z$:
|eFce/
byte[] b = new byte[1024]; 0I"r*;9?K
int nRead; |Fp+9U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4xzoA'Mb@
{ oC1Nfc+
nStartPos += fileAccessI.write(b,0,nRead); ~Jx0#+z9V
//if(nThreadID == 1) P^& =L&U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eh|v>Yew
} #@K %Mx
9 az{j1
0m&W: c
Utility.log("Thread " + nThreadID + " is over!"); {K>}eO:K
bDownOver = true; ]Qh0+!SdG
//nPos = fileAccessI.write (b,0,nRead); NmZowh$M
} \LQ54^eB
catch(Exception e){e.printStackTrace ();} Q*8=^[x
} NaYr$`
} +|TFxaVz
RP~ hi%A
Eh/Z4pzT
//打印回应的头信息 eaCh;IpIf
public void logResponseHead(HttpURLConnection con) !5=S2<UX
{ }J|Pd3Q Sf
for(int i=1;;i++) I&|J +B?#
{ 8;1,saA_9
String header=con.getHeaderFieldKey(i); !t!\b9=
if(header!=null) b[`fQv$G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2mfKy9QxO
Utility.log(header+" : "+con.getHeaderField(header)); O}mz@-Z
else 7':qx}c#!1
break; db5@+_
} pF}WMt
} zJX _EO
db0]D\
KkD&|&!Q7u
public void splitterStop() VJ()sbl{k
{ K%RjWX=H
bStop = true; NX9K%J
} *_CzCl^
~Rk~Zn
yZw5?{g@
} ?'+kZ|
'fr~1pmx#3
t p<wMrq<
/* mPS27z(
**FileAccess.java &(i_s
*//文件访问(定位，写) .<kbYo:MV
package NetFox; PQA}_o
import java.io.*; 6PdLJ#LS
xfADks2w
qpXsQim$~
public class FileAccessI implements Serializable{ R.$1aqA}
8(|lP58~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JJVdq-k+`
RandomAccessFile oSavedFile; PiZU_~A
long nPos; r`5svY
I*hzlE
r%UsUj
public FileAccessI() throws IOException IT=<p60"
{ mVNHH!
this("",0); 8\B]!
} Gx/kel[Y}
@z1pE@7jK
kYnp$8
public FileAccessI(String sName,long nPos) throws IOException $v0beN6MG
{ HGl.dO7NU
oSavedFile = new RandomAccessFile(sName,"rw"); =@y ?Np^A
this.nPos = nPos; >N8*O3
oSavedFile.seek(nPos); \zx$]|AQ
} m*H' Cb
?:+sjHzXT
\<0xg[
public synchronized int write(byte[] b,int nStart,int nLen) c01i!XS
{ G7uYkJO
int n = -1; ;?.w!|6
try{ 32x[6"T
oSavedFile.write(b,nStart,nLen); hG8<@
n = nLen; lNba[;_
} bK#SxV
catch(IOException e) GW\66$|
{ J`xCd/G
e.printStackTrace (); w~wg[d
} "'v^X!"
T3,}CK#O
L. DD
return n; +\)a p
} cT(=pMt8>
KuJNKuHa.
:jr`}Z%;y
} +Hkr\
GvI8W)d3,R
PB?92py&
/* s|\\"3
**SiteInfoBean.java fOJTy0jX8
*/ v$~$_K
package NetFox; eI3ZV^_Ps
gnN"6r1
rBUWzpE"
public class SiteInfoBean { z=yE- I{
O 8XHaVLg3
*~0U4kw+
private String sSiteURL; //Site's URL 7Xf52\7n
private String sFilePath; //Saved File's Path Kn,td:(
private String sFileName; //Saved File's Name b!oj3|9
private int nSplitter; //Count of Splited Downloading File 9|NH5A"H.
?4cj"i
\qz! v
public SiteInfoBean() |qz&d=>
{//nSplitter的缺省值为5 {@ Z=b5/P
//default value of nSplitter is 5 oe<DP7e
this("","","",5); a4\j.(w)$D
} X+kgx!u'y
2Og<e|
,#U[)}im
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W^YaC (I
{ RmRPR<vGW
sSiteURL= sURL; $0XR<D
sFilePath = sPath; wDDNB1_E
sFileName = sName; NOFuX9/'w
this.nSplitter = nSpiltter; #7['M;_
`!Yd$=*c_&
=z[$o9
} eI,H
2{<o1x,Ym
\![ p-mW{
public String getSSiteURL() l1vI
{ DR7JEE
return sSiteURL; ?azcWf z0
} 3 #"!Hg
>!Dp'6
q~`dxq`}
public void setSSiteURL(String value) <b:xyHS
{ bs0[ a 1/
sSiteURL = value; @Yn+ir0>O
} V5'(op/
mgMa)yc!dp
otX/sg.B*
public String getSFilePath() jss.j~8
{ xVk5%
return sFilePath; Ey=ymf.}
} qe'RvBz
3~1Gts
Y_)xytJ$
public void setSFilePath(String value) +U)4V}S)
{ M+*K-zt0
sFilePath = value; 1my1m
} 8SA" bH:
+o?;7
n8tw8o%&[
public String getSFileName() 9yz@hdG
{ %n6NVi_[
return sFileName; /@B2-.w
} C5g9Gg
! (Q[[M
$0k7W?tu
public void setSFileName(String value) \q\"=
{ +)LCYDRV7
sFileName = value; 0O[le*3b
} YSrjg|k*
&\%\"Zh
""A6n{4
public int getNSplitter() %JgdLnQE
{ \)?+6D'#
return nSplitter; )-0+O=v
} /_qHF-
3N5@<:2`
P=PeWX*L<Z
public void setNSplitter(int nCount) v*OV\h.
{ !_FTy^@c2
nSplitter = nCount; nxB[To*P
} zz!jt A
} *d`KD64
bp<,Xfl
zhJ0to[%?
/* 5|cRHM#
**Utility.java 'E&tEbY
*/ AGm=0Om
package NetFox; *?\u5O(
N<ux4tz
,}O33BwJp
public class Utility { C`R<55x6
iL2__TO
A{e>7Z72
public Utility() w3z'ZCcr;"
{ ':3[?d1Es
G<* Iw>ep
C1+f\A|9FP
} .9N7`
>bd@2au9!
//线程睡眠 ~sZ$`t
public static void sleep(int nSecond) y+Hz(}4
{ D(OJr5Gg
try{ 1$+8wDVwad
Thread.sleep(nSecond); @+l=R|
} }LeS3\+UHl
catch(Exception e) :t<S
{ Bgn%d4W;G
e.printStackTrace (); vw4b@v-XQ3
} _-3n'i8
} 4$WR8
?O3d Sxi
//日志 <nb%$2r1
public static void log(String sMsg) K8Q3~bMf
{ P@f#DX )
System.err.println(sMsg); k'k}/Hxub
} C fM[<w
KyyVO"
_9JFlBx
public static void log(int sMsg) U1HG{u,"y
{ D6H?*4f]
System.err.println(sMsg); $8xb|S[
} p_(En4QSH
} rlGv6)vb
gO)":!_n W
)$1>6C\
/* T2/:C7zL
**TestMethod.java !n`|k
*/ 22=sh;y+2
package NetFox; *c [^/
J8i,[,KcE
~\8(+qIv%f
public class TestMethod { d,?Tq
d#]hqy
:vX%0|
public TestMethod() #\`kg#&
{ ///xx/weblogic60b2_win.exe ZX64kk+
try{ fIl!{pv[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jw9v&/-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _Z!@#y@j
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8#VD u(
fileFetch.start(); 2aX*|DGpw
} ~!!\#IX
catch(Exception e){e.printStackTrace ();} dJ m9''T')
fBctG~CJH
b,YNCb]H
} 0#Lmajs
aZCq{7Xs
R"9wVM;*c
public static void main(String[] args) XL^05
{ D%nd7 |
new TestMethod(); gFKJbjT|
} PkI+z_
} v&'#Gg
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