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)); l\Q--
} W8@o7svrh
for(int i=0;i<nEndPos.length-1;i++) M%U1?^j8
{ +2qCH^80
nEndPos = nStartPos[i+1]; z 1~2w:
} VL[}
nEndPos[nEndPos.length-1] = nFileLength; Wu{cE;t
} Rxl )[\A*
} n7CwGN%
lhp.zl
^V5VRGq
//启动子线程 JemB[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \dB)G<_
for(int i=0;i<nStartPos.length;i++) ,V>7eQt?
{ sI&|qK-(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Qx]"ZP%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hzn6H4Rc
nStartPos,nEndPos,i); R6xJw2;_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !4?QR
fileSplitterFetch.start(); h;+bHrKji
} |qp^4vq.p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SU8vz/\%y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %o4d(C B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KKFV+bK)
nEndPos = " + nFileLength); :iKk"r,2P[
// fileSplitterFetch[nPos.length-1].start(); xE0'eC5n^
l-~ o&n
#9's^}i
//等待子线程结束 eeix-Wt*E
//int count = 0; nQHQVcDs8
//是否结束while循环 54^2=bp
boolean breakWhile = false; U?WS\Jji3!
%UO ;!&K
Z(~v{c %<
while(!bStop) dPVl\<L1
{ HZ_,f"22
write_nPos(); n _H]*~4F
Utility.sleep(500); oMw#ROsvC
breakWhile = true; 3-%F)@n
lk(q>dvK
Z%_m<Nf8T
for(int i=0;i<nStartPos.length;i++) s|q]11r+H
{ V1d{E 0lM
if(!fileSplitterFetch.bDownOver) %F.^cd"
{ RaX:&PE
breakWhile = false; ,cF $_7M
break; JvI6+[
} 'Cq)/}0
} C7hJE-
if(breakWhile) >EJ`Z7E6
break; "QV?C
Gc1!')g!
sX,."@[
//count++; @D3|Ak1
//if(count>4) 0|L%)'F
// siteStop(); Jh6 z5xUV
} 1>"Yw|F-|3
aj\ zc I
Wh7}G
System.err.println("文件下载结束！"); Y}aaW[
} &4 ~C%{H3
catch(Exception e){e.printStackTrace ();} `#Yv(a2TY
} V=+wsc
k%-S7iQ
)e|n7|} $
//获得文件长度 w~lxWgaY7
public long getFileSize() aR@s. ll
{ o;^k"bo6
int nFileLength = -1; wq6.:8Or-]
try{ 9Z_!}eY2mc
URL url = new URL(siteInfoBean.getSSiteURL()); wV&UB@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q"Ur*/-U
httpConnection.setRequestProperty("User-Agent","NetFox"); {] Zet}2
% a9C]?
Mu>WS)1lS
int responseCode=httpConnection.getResponseCode(); 2 yY.rs
if(responseCode>=400) 0;6^fiSY;
{ N Dg*8i
processErrorCode(responseCode); QV_e6r1t#m
return -2; //-2 represent access is error C3#mmiL-
} qe@ctHpn
hp<NVST
K[G=J
String sHeader; rO;Vr},3\%
.~L^h/)Gjy
'UN 'gXny
for(int i=1;;i++) c1CUG1i
{ TQjM3Ri=V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fdCN?p[_
//Utility.log(in.readLine()); Ac,Qj`'V
sHeader=httpConnection.getHeaderFieldKey(i); uLK4tQ
if(sHeader!=null) LNU#NJ^Axt
{ u&7c2|Q
if(sHeader.equals("Content-Length")) JPt0k
{ zo{WmV7[|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #sg^l>/*
break; ~ 6`Ha@
} ex}6(;7)O
} 2dpTU=K4
else <lxE^M
break; ~UhTy~jya
} ^XbN&'^,HL
} l^"HcP6
catch(IOException e){e.printStackTrace ();} F~O}@e{
catch(Exception e){e.printStackTrace ();} due'c!wW
Q&d"uLsx
aIsT"6A~{
Utility.log(nFileLength); D)my@W0,
QaAWO
YlP8fxS
return nFileLength; <6(&w9WY
} Co%EJb"tk
8G6[\P3fQ
2TxHY|4
//保存下载信息（文件指针位置） dEuts*@Q
private void write_nPos() #y4+O;{
{ Ki_8g
try{ cf7UV6D g
output = new DataOutputStream(new FileOutputStream(tmpFile)); hCX_^%
output.writeInt(nStartPos.length); <`/22S"
for(int i=0;i<nStartPos.length;i++) 'A}@XGE:p
{ Sph:OX8
// output.writeLong(nPos); Vr1yj
output.writeLong(fileSplitterFetch.nStartPos); zG0191f
output.writeLong(fileSplitterFetch.nEndPos); q8_8rp-@
} <JyF5
output.close(); d4]9oi{}
} kTQvMa-X9D
catch(IOException e){e.printStackTrace ();} OU /=wpt
catch(Exception e){e.printStackTrace ();} k:JlC(^h
} cIJqF.k
9R6]OL)p
y~ZYI]` J
//读取保存的下载信息（文件指针位置） "N\tR[P!
private void read_nPos() o(5eb;"yi>
{ %l.5c Sn@
try{ Vw~st1",[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wm<`0}
int nCount = input.readInt(); $QB~ x{v@n
nStartPos = new long[nCount]; %x2_njDd
nEndPos = new long[nCount]; #3WKm*T/
for(int i=0;i<nStartPos.length;i++) F=qG+T
{ 0zCmU)ng
nStartPos = input.readLong(); l2lyi
nEndPos = input.readLong(); TODTR7yGo
} m+ww
input.close(); ; wpX
} ]?$eBbt
catch(IOException e){e.printStackTrace ();} PAUepO_
catch(Exception e){e.printStackTrace ();} {"x>ewAf
} 4U1!SR]s
`YinhO:Z
OlwORtWzZ
private void processErrorCode(int nErrorCode) |sIr}}
{ f#mcWL1}
System.err.println("Error Code : " + nErrorCode); u#c3T'E
} (> {CwtH][
MkCq$MA
erW[q
//停止文件下载 s?g`ufF.t
public void siteStop() {@7{!I|eD
{ s,*kWy"jp
bStop = true; 6L)]nE0^
for(int i=0;i<nStartPos.length;i++) jwe^(U
fileSplitterFetch.splitterStop(); tU :,s^E"#
fZH";_"1
3r[}'ba\
} H}[kit*9
} 5jb/[i^V
//负责部分文件的抓取 |~Op|gs
**FileSplitterFetch.java 0';U3:=i,
*/ I5$@1+B
package NetFox; r{Cbx#;
H1bPNt63
@0mR_\u\
import java.io.*; c2aW4TX2
import java.net.*; !4blX'<w
uoIvFcb^
'0juZ~>}
public class FileSplitterFetch extends Thread { TO|&}sDh
LG/6_t}
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String sURL; //File URL vp>,}nx4
long nStartPos; //File Snippet Start Position 1lJY=`8qa
long nEndPos; //File Snippet End Position M2.Pf s
int nThreadID; //Thread's ID D@]*{WO
boolean bDownOver = false; //Downing is over {r$n $
boolean bStop = false; //Stop identical fF"\$Ny
FileAccessI fileAccessI = null; //File Access interface <A_LZi
$<~o,e-4
r@XH=[:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _eE hIQ9
{ {);S6F$[3
this.sURL = sURL; J!5>8I(_wX
this.nStartPos = nStart; 8)1k>=
this.nEndPos = nEnd; ^Iz(V2
nThreadID = id; V\ 7O)g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C]xKdPQj%
} ZMI!Sl
9AxeA2/X
KqE5{ q
public void run() )225ee>
{ bi^Xdu
while(nStartPos < nEndPos && !bStop) k!^Au8Up?
{ .+'`A"$8
LWpM-eW1q
/tu+L6
try{ has \W\(
URL url = new URL(sURL); ^F*G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %pR:.u|
httpConnection.setRequestProperty("User-Agent","NetFox"); :+G1=TuXw~
String sProperty = "bytes="+nStartPos+"-"; }aPx28:/
httpConnection.setRequestProperty("RANGE",sProperty); FBR]) h'Z
Utility.log(sProperty); 7LQLeQvB
Fk(+S:{yQ
&6yh4-(7
InputStream input = httpConnection.getInputStream(); \}:&Hl+
//logResponseHead(httpConnection); 7<ZP(I5X
RkrZncBgV<
z&3in
byte[] b = new byte[1024]; Q}A*{9#|
int nRead; SXA`o<Ma
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AaVj^iy/X
{ $Ka-ZPy<#
nStartPos += fileAccessI.write(b,0,nRead); RP"YSnF3
//if(nThreadID == 1) U|Du9_0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tY1M7B^~
} IC1oW)
1236W+
[+q':T1W-
Utility.log("Thread " + nThreadID + " is over!"); >AbgJ*X.
bDownOver = true; @Yv.HhO9
//nPos = fileAccessI.write (b,0,nRead); 7({"dW
} %LH~Im=
catch(Exception e){e.printStackTrace ();} Spnshv8
} Nan@SuKY
} %`kO\q_
E*uz|w3S)Y
x}8 U\
//打印回应的头信息 sNet[y:O3
public void logResponseHead(HttpURLConnection con) w;LIP!T#
{ Jj_ t0"
for(int i=1;;i++) O,&nCxB]
{ H\zV/1~Y
String header=con.getHeaderFieldKey(i); .%.bIT
if(header!=null) ?8g*"&cn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l;N?*2zm[
Utility.log(header+" : "+con.getHeaderField(header)); '_f]qNy
else JDQ7
break; ot"3 3I
} E3):8>R;1
} N3_rqRd^
]dx6E6A,
OwdA6it^f
public void splitterStop() B.e3IM0
{ ({GN.pC(
bStop = true; 3X0"</G6
} cTU%=/gbc<
}.nHT0l
IQ${2Dpg[
} f.Uvf^T}2
mHm"QBa!
q0Hor
/* 8"fZ>XQ
**FileAccess.java _y,?Cj=u|
*//文件访问(定位，写) &!@7+'])
package NetFox; J6WyFtlyLc
import java.io.*; ^7qqO%
/$q9 Kxb
z1-JoZ
public class FileAccessI implements Serializable{ W^es"\
4x`.nql
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~ sC<V
RandomAccessFile oSavedFile; Sh]g]xR
long nPos; U1.w%b,
K;n5[o&c
%Ob#GA+
public FileAccessI() throws IOException MPn 6sf9M
{ $69ef[b
this("",0); |?kZfr&9q
} lrE|>R
_YT9zG
1]yjhw9g
public FileAccessI(String sName,long nPos) throws IOException K4H U9!
{ P ]prrKZe,
oSavedFile = new RandomAccessFile(sName,"rw"); f`[gRcZ-
this.nPos = nPos; No'^]r
oSavedFile.seek(nPos); ITq$8
} _6"YWR
-f4>4@y
t$*V*gK{
public synchronized int write(byte[] b,int nStart,int nLen) ;'|Mt)\
{ uia[>&2
int n = -1; 3hPj;-u
try{ x'uxSeH$
oSavedFile.write(b,nStart,nLen); M.[A%_|P
n = nLen; x c[BQ|P=
} G T3wJQ5N
catch(IOException e) opQdym
{ ](z?zDk
e.printStackTrace (); bSKe@4C
} ]xYm@%>6
X-Q;4M-CJ
:.K#=ROP
return n; Yw\7`
} kJOSGrg
5W(S~}
ToNRY<!
} h|DKD.
-%h0`hOG{
60A E~
/* UP*\p79oO
**SiteInfoBean.java nj@l5[
*/ +dt b~M
package NetFox; cSkJlhwNn
}'FNGn.~#
C8J3^?7E
public class SiteInfoBean { >`@c9 m
tR;? o,T
v)TFpV6b{p
private String sSiteURL; //Site's URL EZz`pE
private String sFilePath; //Saved File's Path }EW@/; kC
private String sFileName; //Saved File's Name M< T[%)v
private int nSplitter; //Count of Splited Downloading File rLy<3
7n_'2qY
ZgXn8O[a
public SiteInfoBean() YTtuR`
{//nSplitter的缺省值为5 syseYt]
//default value of nSplitter is 5 Yy_o*Ozq
this("","","",5); z@_9.n]
} 6*cY[R|q!
@eQo
w'Cn3b)`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RCS91[
{ f a9n6uT
sSiteURL= sURL; cITF=Ez
sFilePath = sPath; :EXH8n&|
sFileName = sName; N~w4|q!]
this.nSplitter = nSpiltter; Fp`MX>F
bc".R]
@`</Z)
} $oJ)W@>
)bM #s">Y
<Bmqox0
public String getSSiteURL() icX$<lD
{ LPOZA`
return sSiteURL; |H,g}XWMU
} K]b_JDEk
azUEp8`|
V&' :S{i
public void setSSiteURL(String value) =Wl*.%1 b
{ SSS)bv8m
sSiteURL = value; Fe4QWB6\U
} >/kwy2
7=o2$
4/Vy@h"A3
public String getSFilePath() hKT]M[Pv
{ N'#Lb0`B
return sFilePath; CD]2a@j{
} =h083|y>
'pUJlPGx
6iozb~!Rr
public void setSFilePath(String value) BBub'
{ Qe~2'Hw#9
sFilePath = value; Qoj}]jve
} 8Jz/'
/$IF!q+C
is3nLm(
public String getSFileName() %PsDS
{ QSn%~o05
return sFileName; O$><E8q
} t*fG;YOg
+3c!.] o;
x bG'![OX
public void setSFileName(String value) %Jrdr`<
{ NMSpi[dr
sFileName = value; UL/|!(s
} O\5*p=v
]g>@r.Nc
%HRFH
public int getNSplitter() {(DD~~)D
{ 3wS{@'
return nSplitter; ! Z e
} S;o U'KOY
)$#r6fQO
dh7PpuN{
public void setNSplitter(int nCount) !U,^+"l'GP
{ -jZP&8dPH
nSplitter = nCount; 3X+uJb2
} !Q,A#N(
} S=Ihg
@~!1wPvF`I
5-277?
/* >.D0McQg
**Utility.java ;w(]z
*/ + *YGsM`E9
package NetFox; BO5gwvyI
@-z#vJ5Qe{
AUloP?24
public class Utility { 728}K^7:
iA~b[20&
imx/hz!
public Utility() $jYwV0
{ ub"(,k P
s$Il;
{__Z\D2I
} 1}E`K#
JJnZbJti
//线程睡眠 SL;\S74
public static void sleep(int nSecond) 0Fw0#eE
{ Ozk^B{{o
try{ o6pnTu
Thread.sleep(nSecond); TQ?D*&
} H=vrF-#
catch(Exception e) :E|HP#iwu
{ 1i}Rc:
e.printStackTrace (); mT.p-C
} IJ^KYho
} }2Lh'0 xY
)x.}B4z
//日志 _tR%7%3*
public static void log(String sMsg) U.oxLbJ`
{ (~oUd4
System.err.println(sMsg); ]fXMp*LvY
} rK*s/mX <
+#5nk,1c>
j+3~
public static void log(int sMsg) ]JX0:'x^
{ TEZ^Ia
System.err.println(sMsg); /Yk2 |L
} Kp*nOZ
} "C$z)
47_4`rzy;
?~rF3M.=|
/* O)MKEMuA
**TestMethod.java e~r%8.Wm
*/ 5_+vjV;5
package NetFox; -OpI,qyS
4#uWj?u
PsDks3cG
public class TestMethod { ?)#dP8n
b 2n.v.$G
j380=?7
public TestMethod() Qp7|p
{ ///xx/weblogic60b2_win.exe cL&V2I5O
try{ Q5e ,[1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %t0Fx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R@``MC0
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?;.j)
fileFetch.start(); V *=To
} X75>C<
catch(Exception e){e.printStackTrace ();} uROt h_/
tRYMK+
>9W ;u`
} . m_y5J
9`\hG%F
@<--5HbX
public static void main(String[] args) Nt#zr]Fz
{ yy4QY%
new TestMethod(); ?7@Y=7BS4
} @EzSosmF
} )t{oyBT
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