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)); fZ. ONq
} *](iS
for(int i=0;i<nEndPos.length-1;i++) 7Ix973^
{ M?qy(zb
nEndPos = nStartPos[i+1]; $u.z*b_yy
} g5yJfRLxp
nEndPos[nEndPos.length-1] = nFileLength; ]?*wbxU0
} 7 3m1
} :%.D78&
?8$Q-1=
z@Y;r=v
//启动子线程 Vc2`b3"Br
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m2o0y++TjW
for(int i=0;i<nStartPos.length;i++) ]tD]Wx%
{ 3u;oQ5<(v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =}*0-\QG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <qSC#[xu
nStartPos,nEndPos,i); Dj+f]~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Y &d=
fileSplitterFetch.start(); 1qch]1 ^G
} 0mnw{fE8_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]! dTG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); / +\9S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w@b)g
nEndPos = " + nFileLength); (?c-iKGc
// fileSplitterFetch[nPos.length-1].start(); OH88n69
G9lUxmS<
7"mc+QOp
//等待子线程结束 Zh,71Umz
//int count = 0; g ?k=^C
//是否结束while循环 IU[ [H#
boolean breakWhile = false; <N)oS-m>
Ei|\3Kx
]q.0!lh+WL
while(!bStop) ZEQEx]Y
{ s>en
write_nPos(); H.c7Nle
Utility.sleep(500); 25T18&R
breakWhile = true; G"6 !{4g
O}P`P'Y|'
*fdTpXa
for(int i=0;i<nStartPos.length;i++) ~BF&rx5Q
{ Rv=YFo[B
if(!fileSplitterFetch.bDownOver) ;,TFr}p`
{ \8 ":]EU
breakWhile = false; >V937
break; yuVs YV@"
} GmG5[?)
} AdmC&!nH
if(breakWhile) y(&Ac[foS}
break; 6mE\OS-I
y2v^-q3
iwq!w6+
//count++; F:VIzyMq<
//if(count>4) GeqPRah
// siteStop(); :Al!1BJQ
} O8o3O 6[Y
p'k0#R$
(mOtU8e
System.err.println("文件下载结束！"); dveiQ
} 5\v3;;A[
catch(Exception e){e.printStackTrace ();} : +u]S2u{
} &L:!VL{I
@co S+t
G)YcJv7
//获得文件长度 @7u0v
public long getFileSize() N;R^h? '
{ \GBuWY3B
int nFileLength = -1; [RL9>n8f
try{ >sF)BoLc
URL url = new URL(siteInfoBean.getSSiteURL()); cS$_\65
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0a7Ppntb@
httpConnection.setRequestProperty("User-Agent","NetFox"); 9!GM{
5N]"~w*
jylD6IT
int responseCode=httpConnection.getResponseCode(); UBs4K*h|
if(responseCode>=400) QnDg6m)+
{ i@q&5;%%
processErrorCode(responseCode); )_:NLo:
return -2; //-2 represent access is error K@2),(z
} Fcx&hj1gQ
}qUX=s GG
$j~RWfw-
String sHeader; jo7\`#(Q
t:S+%u U
LP-o8c
for(int i=1;;i++) =AT."$r>
{ b$7 +;I;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IgzQr>
//Utility.log(in.readLine()); zqku e%^?-
sHeader=httpConnection.getHeaderFieldKey(i); 7^285)UQA
if(sHeader!=null) NHt\ U9l'
{ rjP/l6 ~'
if(sHeader.equals("Content-Length")) @CoIaUVP
{ 3^ClAE"8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7=uj2.J6
break; JT?h1v<H]
} K:M8h{Ua
} =D(j)<9$A
else pYg/Zm Jd
break; ]|@^1we
} "4Nt\WQ
} +_!QSU,@
catch(IOException e){e.printStackTrace ();} XZf$K_F&M
catch(Exception e){e.printStackTrace ();} jdN`mosJ
YUb_y^B^
T|$H#n}
Utility.log(nFileLength); *a)n62
,6/V"kqIP
TC('H[ ]
return nFileLength; ZcsZ$qt^
} y5r4&~04
R_KH"`q
$qiya[&G4
//保存下载信息（文件指针位置） im8CmQ
private void write_nPos() B~mj 8l4
{ :s,Z<^5a)g
try{ n<,BmVQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,uvRi)O>a
output.writeInt(nStartPos.length); zA 3_Lx!
for(int i=0;i<nStartPos.length;i++) kM6 Qp
{ NbobliC=
// output.writeLong(nPos); VVZ'i.*_3?
output.writeLong(fileSplitterFetch.nStartPos); hgmCRC
output.writeLong(fileSplitterFetch.nEndPos); W^Yxny
} D9df=lv mD
output.close(); ~[ jQ!tz
} K9[UB
catch(IOException e){e.printStackTrace ();} H}!r|nG
catch(Exception e){e.printStackTrace ();} EnR}IY&sI
} _t$sgz&
!if
pmM9,6P4@
//读取保存的下载信息（文件指针位置） b}f~il
private void read_nPos() SBpL6~NW
{ \zY!qpX<
try{ ZNoDFf*h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,}PgOJZ
int nCount = input.readInt(); s%S
nStartPos = new long[nCount]; _#niyW+?~
nEndPos = new long[nCount]; Ba,`TJ%y
for(int i=0;i<nStartPos.length;i++) eRYK3W
{ \RiP
nStartPos = input.readLong(); _-D{-Bu#
nEndPos = input.readLong(); uZ5p#M_
} +0&/g&a\R
input.close(); eDMO]5}Ht
} ]lbuy7xj63
catch(IOException e){e.printStackTrace ();} eavV?\uV%
catch(Exception e){e.printStackTrace ();} . vV|hSc
} |=w@H]r
y `UaB3q
=&]L00u.
private void processErrorCode(int nErrorCode) ^c<Ve'-
{ 2HdC |$_+
System.err.println("Error Code : " + nErrorCode); /(cPfZZ
} 8Wx=p#_
A<{{iBEI`
UpG~[u)%@
//停止文件下载 :]KAkhFkbb
public void siteStop() L#J1b!D&<6
{ fl(wV.Je|
bStop = true; \Z/@C lCm
for(int i=0;i<nStartPos.length;i++) uph(V
fileSplitterFetch.splitterStop(); *T/']t
Wc#24:OKe3
w}KkvP^
} wz%-%39q%
} _U(
//负责部分文件的抓取 Nc`L;CP
**FileSplitterFetch.java [6fQ7uFMM8
*/ gJXaPJA{
package NetFox; +rd+0 `}C
AKC`TA*E
\~W'v3:W
import java.io.*; 8=l%5r^cq
import java.net.*; kj_c%T ]/
wp_0+$?s
Upe%rC(
public class FileSplitterFetch extends Thread { u_enqC3
M >u_4AY
QV!up^Zso
String sURL; //File URL 2ESo2
long nStartPos; //File Snippet Start Position >A= f1DF
long nEndPos; //File Snippet End Position ^sw?gH*
int nThreadID; //Thread's ID EwN}l
boolean bDownOver = false; //Downing is over aOp\91
boolean bStop = false; //Stop identical ~Y;*u]^
FileAccessI fileAccessI = null; //File Access interface uFE)17E
se)TzI^]b@
ep8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1#x0q:6
{ F%|h;+5
this.sURL = sURL; D~m*!w*
this.nStartPos = nStart; qm}@!z^
this.nEndPos = nEnd; d0D]Q
nThreadID = id; ^!d3=}:0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vN:Ng
} >6T8^Nt
)GpK@R]{
d=(mw_-?
public void run() LoV<:|GTI
{ occ7zcA
while(nStartPos < nEndPos && !bStop) ]Um/FAW
{ jd:6:Fm
R&&4y 7
A^g(k5M*
try{ 8LKiS
URL url = new URL(sURL); K1KreYlF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]kSGR
httpConnection.setRequestProperty("User-Agent","NetFox"); L0,'mS
String sProperty = "bytes="+nStartPos+"-"; 2G7Wi!J
httpConnection.setRequestProperty("RANGE",sProperty); &d!GImcxQ
Utility.log(sProperty); >Tgv11[
ll^#JpT[S
<I?Zk80
InputStream input = httpConnection.getInputStream(); -RwE%cr
//logResponseHead(httpConnection); 0B2t"(&
0kh6@y3
M%HU4pTW#o
byte[] b = new byte[1024]; q~3>R=t
int nRead; ye&;(30Oq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9*gZ-#
{ jA1+x:Wq
nStartPos += fileAccessI.write(b,0,nRead); -n 1v3
//if(nThreadID == 1) P:c w|Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M3\AY30L
} 79gT+~z
N8jIMb'<
zX[U~.
Utility.log("Thread " + nThreadID + " is over!"); ';CNGv -
bDownOver = true; 0mE 0 j
//nPos = fileAccessI.write (b,0,nRead); pBHRa?Y5
} x5Bk/e'
catch(Exception e){e.printStackTrace ();} 3og.y+.=U.
} ZK,G v
} 6P3*Z
oJ^P(]dw
X?O[r3<
//打印回应的头信息 @d'j zs
public void logResponseHead(HttpURLConnection con) H_a[)DT
{ Q,g\
for(int i=1;;i++) E GU2fA7x
{ ytImB`'\
String header=con.getHeaderFieldKey(i); 5m@V#2^P
if(header!=null) ?<!|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oH@78D0A
Utility.log(header+" : "+con.getHeaderField(header)); Nn6%9PX_)
else kiEa<-]
break; {7[Ox<Ho
} N2G{<>=
} $'vU2L
F9PxSk_\9
V~GDPJ+
public void splitterStop() /~1+i'7V.,
{ MgZ/(X E
bStop = true; 4#D,?eA7
} Mx}gN:Wt
5P2K5,o|n~
&>O+}>lr9
} cAw/I@jG
=;L|gtH"
4W75T2q#
/* 2?C)&
**FileAccess.java 97Vtn4N3
*//文件访问(定位，写) /vt3>d%B;
package NetFox; :gv"M8AP
import java.io.*; F59 TZI
$4\j]RE!
l1I#QB@5n
public class FileAccessI implements Serializable{ iZmcI;?u
=pNY eR_[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xw1*(ffk
RandomAccessFile oSavedFile; *~`(RV
long nPos; h[ ZN+M
?6!LL5a.
P}iE+Z3
public FileAccessI() throws IOException +`4A$#$+y
{ T{"(\X$
this("",0); 6]N.%Y[(
} kZ~~/?B
9r9NxKuAO
Z+SRXKQ
public FileAccessI(String sName,long nPos) throws IOException / {%%"j
{ y =@N|f!
oSavedFile = new RandomAccessFile(sName,"rw"); 4H/OBR
this.nPos = nPos; SbZ6t$"
oSavedFile.seek(nPos); u*R_\*j@
} c-w)|-ac.
z:O8Ls^\T
)7@0[>
public synchronized int write(byte[] b,int nStart,int nLen) )oZ dj`
{ lZ0 =;I
int n = -1; *pd@.|^)m
try{ 3`HV(5U[
oSavedFile.write(b,nStart,nLen); gw(z1L5 n
n = nLen; K3C<{#r
} <@}9Bid!o
catch(IOException e) al0L&z\
{ XW9!p.*.U
e.printStackTrace (); ,4rPg]r@
} }Jw,>}
]n~V!hl?A
}JfjX'
return n; G$PE}%X
} k)u[0}
=Qq+4F)MD
Xj*Wu_
} hZ3bVi)L\
5;?yCWc
1M-pr 8:6s
/* ,Q B<7a+I
**SiteInfoBean.java G3]4A&h9v~
*/ E7hhew
package NetFox; zDp2g)
Z)!C'cb
J4utIGF
public class SiteInfoBean { :N@^?q{b
z#N@ 0R
3T 9j@N77
private String sSiteURL; //Site's URL ^8tEach
private String sFilePath; //Saved File's Path C~[,z.FvO
private String sFileName; //Saved File's Name lr?;*f^3
private int nSplitter; //Count of Splited Downloading File SuznN L=/$
Cw%{G'O
c,22*.V/
public SiteInfoBean() zi:BF60]=
{//nSplitter的缺省值为5 0V]s:S
//default value of nSplitter is 5 l%ZhA=TKQ
this("","","",5); J1kM\8%b\
} IID5c" oR
)Z$!PqRw@u
67TwPvh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +(*DT9s+
{ iE{&*.q_}>
sSiteURL= sURL; ,Q,^3*HX9}
sFilePath = sPath; Q?T]MUY(L
sFileName = sName; VpUAeWb
this.nSplitter = nSpiltter; &zhAh1m
8fb'yjIC
>7r!~+B"9'
} ,[Fb[#Qqb
l,:F
Q&&@v4L
public String getSSiteURL() JRFtsio*
{ +V+a4lU14
return sSiteURL; /=h` L,
} zQA`/&=Y
H"KCK6
OB7hlW
public void setSSiteURL(String value) r>\bW)e
{ iLz@5Zj8
sSiteURL = value; 23?rEhKe
} :]c3|J
h~26WLf.
:EH=_"
public String getSFilePath() /bEAK-
{ G:JR7N$
return sFilePath; k8Xm n6X
} 1cGmg1U;
:LTN!jj
nm+s{
public void setSFilePath(String value) G`zm@QL
{ .2pK.$.
sFilePath = value; 2%>FR4a
} />Nt[o[r
R4@6G&2d>
^(<f/C)i
public String getSFileName() @KA4N`
{ V:27)]q
return sFileName; S$k&vc(0
} jtc~DL
K>9 ()XT)
fatf*}eln
public void setSFileName(String value) >MK98(F
{ 9Ee'Cm
sFileName = value; sr}E+qf
} i&k7-<
6Iw\c
TKjFp%
public int getNSplitter() ~4"dweu?
{ qVPeB,kIz
return nSplitter; rbQR,Nf2x
} <1pEwI~
RL<c>PY
Ha ]YJ}
public void setNSplitter(int nCount) 5?L<N:;J_
{ KU;9}!#
nSplitter = nCount; d1kJRJ
} iCyfOh
} 0g\(+Qg^
[r-p]"R
1sCR4L:+
/* >Se,;cB'/]
**Utility.java T)CP2U
*/ /@Zrq#o zx
package NetFox; v3qA":(w+(
(ik\|y% A
>j`qh:^
public class Utility { s<Fl p
Kg$Mx
`W-Fssu
public Utility() 4fzZ;2sl}
{ akT6^cP^
"]iB6
B?qjkP
} 5-G@L?~Vw
D6^6}1WI
//线程睡眠 H|D.6^
public static void sleep(int nSecond) +"6`q;p3)
{ \;-|-8Q
try{ 4X$Qu6#i
Thread.sleep(nSecond); -^57oU
} qw8Rlws%
catch(Exception e) d| {r5[&
{ g*"P:n71
e.printStackTrace (); ]:f%l mEy
} \L\b$4$d
} 0RK!/:'
LK"69Qx?5q
//日志 |I|fMF2K
public static void log(String sMsg) R$Q.sE
{ p$>l7?h
System.err.println(sMsg); @o6L6Y0Naa
} T#)P`q
]q-Y }1di8
:lzrgsW
public static void log(int sMsg) _?OG1t!
{ .6V}3q$-@
System.err.println(sMsg); _l]fkk[T
} f9\X>zzB2|
} hzRYec(
Gbw2E&a
$\! 7 {6a
/* ,: ->ErP
**TestMethod.java m_l[MG\
*/ A4ygW:
package NetFox; P2*<GjV`S/
"T"h)L<
<o= 8FO
public class TestMethod { veRm2LSP
h-D}'R
+U.I( 83F
public TestMethod() 7!$^r$t
{ ///xx/weblogic60b2_win.exe ~= -RK$=
try{ F3N6{ysK#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d:{O\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e!r-+.i(
SiteFileFetch fileFetch = new SiteFileFetch(bean); AvHCO8h|
fileFetch.start(); @gtQQxf"
} pBPl6%C.X-
catch(Exception e){e.printStackTrace ();} 2>H24F
Wr5V`sM
QVE6We
} 3Le{\}-$.
w'3iY,_ufC
-S+zmo8
public static void main(String[] args) - CWywuD
{ y|q3Wa
new TestMethod(); nJLFfXWx
} 8Bg;Kh6B
} \r>6`-cs]
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