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)); =Z2Cg{z
} a)/!ifJ;
for(int i=0;i<nEndPos.length-1;i++) 'WUd7
{ jIaAx_
nEndPos = nStartPos[i+1]; fKb8)PDP
} |1uyJ?%B
nEndPos[nEndPos.length-1] = nFileLength; [}}?a
} F$F,I,$ "
} ' cR||VX
tI~.3+F
<!EdND=
//启动子线程 mfc\w'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IC"bg<L,*
for(int i=0;i<nStartPos.length;i++) &A)AV<=>T
{ 8GgZAu'X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a6cq0g[#z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tN&4t xB
nStartPos,nEndPos,i); ;shhgz$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DD{-xCCR
fileSplitterFetch.start(); * G!C 'w\$
} =dSH8C"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CB]#`|f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rozp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @8{-B;
nEndPos = " + nFileLength); -fKo~\Pr
// fileSplitterFetch[nPos.length-1].start(); agp`<1h9
LX2rg\a+%
sxkWg>
//等待子线程结束 _FR_6*C)5
//int count = 0; p8,Rr{
//是否结束while循环 %/iD@2r
boolean breakWhile = false; uj;tmK>;
yq]=+X>(
jkTC/9AE|
while(!bStop) v"ZNS
{ nI]8w6eCV
write_nPos(); 0vR gmn
Utility.sleep(500); e!k1GTH^
breakWhile = true; Uq/FH@E=
wX<w)@
[QwEidX|
for(int i=0;i<nStartPos.length;i++) )B'&XLK
{ i7D[5!
if(!fileSplitterFetch.bDownOver) wr>[Eo@%\
{ ?i'N9 /(
breakWhile = false; F#NuZ'U
break; t$~CLq5ad
} v_^>*Vm*
} U1nObA
if(breakWhile) &GYnGrw?@
break; %x{jmZ$}
o_ng{SL
F/p/&9
//count++; -@bOFClE
//if(count>4) 6.5E d-
// siteStop(); s R/z)U_
} V9`?s0nn^
Pa)'xfQ$Y6
M18>%zM
System.err.println("文件下载结束！"); 5?l8;xe`{f
} x Zp`
catch(Exception e){e.printStackTrace ();} tBUn KPT
} %vn"tp
|Yb]@9>vn
zu/BDyF
//获得文件长度 ^Mvgm3hg
public long getFileSize() Ln+;HorZ]
{ cvOCBg38BH
int nFileLength = -1; (E(J}r~E
try{ T8^`<gr.
URL url = new URL(siteInfoBean.getSSiteURL()); Ob!NC&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2nra@
httpConnection.setRequestProperty("User-Agent","NetFox"); VN3[B eH
Z-%zR'-?*
65]>6D43
int responseCode=httpConnection.getResponseCode(); xQUskjv/
if(responseCode>=400) s#cb wDT
{ C*X=nezq
processErrorCode(responseCode); Q&5s,)w-
return -2; //-2 represent access is error !#y_vz9
} G]v BI=
iHa:6
?i{/iH~Sf
String sHeader; p C^=?!:U
R1C}S
$U=j<^R}a
for(int i=1;;i++) :%[mc-6.
{ /6y9u}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F:7d}Jx
//Utility.log(in.readLine()); 43.Q);4
sHeader=httpConnection.getHeaderFieldKey(i); ^V}c8 P|
if(sHeader!=null) ]A=yj@o$xN
{ Y;)l
if(sHeader.equals("Content-Length")) P+L#p(K
{ ;~,)6UX7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N?EeT}m_
break; utu V'5GD
} FW"n+7T
} Nn#;Kjul.
else G)IK5zCDd
break; V1#:[o63+
} N&yr?b'!-*
} $;pHv<
catch(IOException e){e.printStackTrace ();} z[Ah9tM%
catch(Exception e){e.printStackTrace ();} 8-B6D~i
=f?vpKq40
*qZBq&7tb
Utility.log(nFileLength); i&TWIl8
cY^'Cj
#=V\WQb
return nFileLength; :u]QEZ@@
} ;#bDz}|\AN
:\Q#W4~p
e_YTh^wU
//保存下载信息（文件指针位置） 6bDizS}
private void write_nPos() dOT7;@
{ i@`qam
try{ %(1Jt"9|
output = new DataOutputStream(new FileOutputStream(tmpFile)); |b4f3n
output.writeInt(nStartPos.length); Skg}/Ek
for(int i=0;i<nStartPos.length;i++) +!Q*ie+q
{ S3UJ)@ E
// output.writeLong(nPos); u!-v1O^[
output.writeLong(fileSplitterFetch.nStartPos); &gF9VY
output.writeLong(fileSplitterFetch.nEndPos); [*J?TNk
} :85QwN]\
output.close(); WF_v>g:g
} gNJdP!(t
catch(IOException e){e.printStackTrace ();} !bIE%cq
catch(Exception e){e.printStackTrace ();} EQtYb"_
} 5?Ukf$)x
oj/#wF+
K&VMhMVb
//读取保存的下载信息（文件指针位置） r=HL!XFk
private void read_nPos() bU\T
{ :K~sazs7J
try{ G0A\"2U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,8.$!Zia
int nCount = input.readInt(); >,ABE2t5
nStartPos = new long[nCount]; e3mFO+
nEndPos = new long[nCount]; i}e/!IVR3
for(int i=0;i<nStartPos.length;i++) LGK&&srJs
{ F/PH=Dk
nStartPos = input.readLong(); T/FZn{I
nEndPos = input.readLong(); u9m ~1\R*
} iR"6VO
input.close(); |xF!3GGms
} v\@pZw=x
catch(IOException e){e.printStackTrace ();} 6zi 5#23
catch(Exception e){e.printStackTrace ();} (tyky&$!
} $V!25jQ
)5NWUuH 5
^(s(4|
private void processErrorCode(int nErrorCode) erKi*GssZ
{ O!t=,F1j
System.err.println("Error Code : " + nErrorCode); S5kD|kJ
} R^mkQb>m.
"G^TA:O:=
c^rWS&)P
//停止文件下载 6RG63+G
public void siteStop() u* G+=aV.6
{ g^}C/~b[
bStop = true; yDJy'Z_F{
for(int i=0;i<nStartPos.length;i++) Gr>CdB>~+
fileSplitterFetch.splitterStop(); ol K+|nR
n.i8?:
.SLpgYFL{
} mo+!79&
} l3*GQ~m7
//负责部分文件的抓取 l<p<\,nV$
**FileSplitterFetch.java $Dd-2p
*/ -&Q+x,.%
package NetFox; ?6]B6
!"o\H(siT
K$:+]fJK
import java.io.*; }g@ '^v
import java.net.*; O c.fvP^ZD
O._\l?m
Qea"49R
public class FileSplitterFetch extends Thread { eY-h<K)y
@lq)L
A;^ iy]"
String sURL; //File URL ]28j$)6
long nStartPos; //File Snippet Start Position oaZdvu@y
long nEndPos; //File Snippet End Position C_'EO<w$
int nThreadID; //Thread's ID VR .t
boolean bDownOver = false; //Downing is over D.-G!0!
boolean bStop = false; //Stop identical >28l9U
FileAccessI fileAccessI = null; //File Access interface 9 *uK]/c
*?*~<R
vaJl}^T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^BM !TQ%!
{ 8;L;R~Q
this.sURL = sURL; PxQQfI>
this.nStartPos = nStart; &CcW(-
this.nEndPos = nEnd; 0b/@QgJ
nThreadID = id; {bADMj1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }n "5r(*^@
} SQhVdYU1'
Faa>bc~E
{6WG
public void run() Zk/ejhy0
{ `N&*+!O%
while(nStartPos < nEndPos && !bStop) $2,tT;50g
{ e&2,cQRFV
Te[v+jgLY,
W/%hS)75
try{ '6})L
URL url = new URL(sURL); 7{(UiQbf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]jY^*o[
httpConnection.setRequestProperty("User-Agent","NetFox"); -8Hc M\b
String sProperty = "bytes="+nStartPos+"-"; |d&C<O;f
httpConnection.setRequestProperty("RANGE",sProperty); ,vO\n^
Utility.log(sProperty); S0Io$\ha
wP*3Hx;S
o&&`_"18
InputStream input = httpConnection.getInputStream(); ^EKRbPA9:<
//logResponseHead(httpConnection); BWvM~no
iC5HrOl6U
%)r:!R~R
byte[] b = new byte[1024]; y/ Bo4fM
int nRead; <ch}]-_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2m]4
{ ErJ/h?+
nStartPos += fileAccessI.write(b,0,nRead); c|JQ0] K
//if(nThreadID == 1) IG# wY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s9a`2Wm
} }^0'IAXi
FwlDP
!mTq6H12 !
Utility.log("Thread " + nThreadID + " is over!"); vBOY[>=
bDownOver = true; !'~Ldl
//nPos = fileAccessI.write (b,0,nRead); 6r`N\ :18
} FZn1$_Svr
catch(Exception e){e.printStackTrace ();} tW4X+d"
} ju'aUzn
} ]hS<"=oj
>zDQt7+g;
CuH4~6
//打印回应的头信息 -3i(N.)<;
public void logResponseHead(HttpURLConnection con) AWi>(wk<
{ c+E\e]{
for(int i=1;;i++) !L8q]]'XM
{ Sir1>YEm
String header=con.getHeaderFieldKey(i); qR!ZtJ5j
if(header!=null) k}F7Jw#.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Z"MO@9:
Utility.log(header+" : "+con.getHeaderField(header)); f|M^UHt8*
else K}cA%Y
break; R;pW,]}g,
} [ i,[^
} E"_{S.Wc
1HKA`]D"p
0?8>{!I
public void splitterStop() _hyqHvP
{ -&`_bf%M
bStop = true; E b:iym0
} \XmplG:
k kAg17 ^
y>x"/jzF#
} iAQ[;M3p
y705
2w3LK2`ZL
/* i KQj[%O
**FileAccess.java u-|%K.A
*//文件访问(定位，写) -%Vh-;Ie(
package NetFox; d@g29rs
import java.io.*; +B " aUF
L=qhb;[L
|Vqm1.1/Zv
public class FileAccessI implements Serializable{ &hkD"GGe
K"XwSZ/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T@.+bD
RandomAccessFile oSavedFile; &Pm@+ML*x
long nPos; P$Vh{]4i{
fsPNxy"_
6]%=q)oL[
public FileAccessI() throws IOException P8ej9ULX,
{ @}H'2V
this("",0); MYvz%7
} t2{(ETV
] 9C)F*r7
zA6C{L G3
public FileAccessI(String sName,long nPos) throws IOException Qc-W2%
{ l<uI-RX"
oSavedFile = new RandomAccessFile(sName,"rw"); Uz,P^\8^$
this.nPos = nPos; Jj[3rt?8
oSavedFile.seek(nPos); Mn/
} gizY4~ j
1}|y^oB\-
yN{**?b
public synchronized int write(byte[] b,int nStart,int nLen) M !"Q7>d
{ mfI[9G
int n = -1; Bf00&PE;
try{ 2=;ZJ
oSavedFile.write(b,nStart,nLen); hfLe<,
n = nLen; sj&(O@~R
} r+[g.`
catch(IOException e) K/C}
{ iUh7eR9
e.printStackTrace (); D9NRM;v
} +qjZ;5(
*!"T^4DEg
> `eo0
return n; faLfdUimJ
} Q+K]:c
uc!6?+0h
,B/TqPP
} ~h8k4eM
,Aq, f$5V
c/bT5TIEWs
/* C$])q`9
**SiteInfoBean.java (AZneK :*
*/ ld(_+<e
package NetFox; / zNVJhC
:/=P6b;
dfVI*5[Z
public class SiteInfoBean { ( zm!_~1
V4"o.G3\o
st"@kHQ3
private String sSiteURL; //Site's URL OI)k0t^;D
private String sFilePath; //Saved File's Path 0K^@P#{hd
private String sFileName; //Saved File's Name D&mPYxXL
private int nSplitter; //Count of Splited Downloading File Fczia0@z
%1;Y`>
wd|^m%
public SiteInfoBean() 5?>Q[a.Ne
{//nSplitter的缺省值为5 "N%W5[C{
//default value of nSplitter is 5 j^8Hjg
this("","","",5); 7SkW!5
} mXJG &EA
x?{l<mc
7]L}~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u];\v%b
{ P!9-!+F"
sSiteURL= sURL; Ve[Kv07
sFilePath = sPath; :X9;KoJl-V
sFileName = sName; U/U_q-z]
this.nSplitter = nSpiltter; 0[ n;ZL~
/8_x]Es/
p|;#frj
} E?K(MT&@
tx1TtWo
_pS)bxw
public String getSSiteURL() d<\X)-"
{ +BI%.A`2
return sSiteURL; 5 YIk
} <Vyl*a{%
/*S6/#
p0Ij4
public void setSSiteURL(String value) '#lEUlB
{ 3WkrG.$[b
sSiteURL = value; q}JP;p(#
} 9~f RYA*
}236{)DuN
Pa\yp?({q
public String getSFilePath() K)`l >o1
{ xWQQX
return sFilePath; M _Lj5`
} uZ1G,9
"[L+LPET
=%FhY^-
public void setSFilePath(String value) _3KfY
{ LwQYO'X
sFilePath = value; `$;%%/tx
} MGKSaP;x
g( eA?
S^e e<%-
public String getSFileName() #{bT=:3a
{ +>mU4Fwp
return sFileName; Z79Y$d>G<E
} %.IW H9P7
7&|&y SCu
d5LL( "
public void setSFileName(String value) [DSzhi]
{ J72kjj&C
sFileName = value; .ddf'$6h
} z{> )'A/
<e8Ux#x/
=p!Hl#
public int getNSplitter() $kQQdF
{ 8`w#)6(V
return nSplitter; l=&Va+K
} 1NlpOVq:)
^''3}<Ep
60p*4>^v
public void setNSplitter(int nCount) zZCssn;[
{ l(tMo7iPa
nSplitter = nCount; DoJ3zYEk
} XlxB%
} s)~H_,
P<xCg
Wf$P+i*
/* ,n{|d33
**Utility.java _3Q8R}
*/ A}03s6^i;
package NetFox; `~W?a
&>auW}r
O`0A#h&No
public class Utility { DVyxe}
)d?L*X~y'
5fhe{d"si
public Utility() T 3+lYE
{ pXxpEv
9d,2d5Y
pB]+c%\
} Je~Ybh
]M9r<x*
//线程睡眠 ZEU/6.
public static void sleep(int nSecond) =g^JJpS
{ {B6tGLt#bf
try{ `OyYo^+D|.
Thread.sleep(nSecond); Rwz (20n\^
} Q(YQ$i"S
catch(Exception e) }W R?n
{ ;=ERm=
e.printStackTrace (); 3H/4$XJB
} <Okl.Iz>
} ji|tc9#6
mOi 8W,2
//日志 -jsk-,
public static void log(String sMsg) lMBXD?,,J
{ wS1zd?
System.err.println(sMsg); !"x&tF
} ?qjlWCV|e
A4|a{\|$
|b:91l
public static void log(int sMsg) .EoLJHL }
{ V2|XcR
System.err.println(sMsg); %g*AGu`
} ZiOL7#QWX
} onAC;<w
1 9C=' TMS
VpkkiN
/* -gKo@I
**TestMethod.java +gOv5Eno-
*/ [8Zvs=1
package NetFox; f"G?#dW/1
aC2\C=ru_
N-Nq*
public class TestMethod { GE[J`?E]
f'<MDLl
VBK9te,A
public TestMethod() nZ2mY!*
{ ///xx/weblogic60b2_win.exe kMLWF
try{ \.<V~d?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =9JKg4I6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r/vRaOg>X
SiteFileFetch fileFetch = new SiteFileFetch(bean); r8E)GBH-|
fileFetch.start(); /Z*XKIU6v/
} g4 |s9RMD
catch(Exception e){e.printStackTrace ();} 7 a}qnk%
DVq5[ntG
dLMKfh/4Q
} 2,X~a;+
eD481r
L(2KC>GvA
public static void main(String[] args) %kJ_o*"
{ pkL&j<{
new TestMethod(); Yw\PmRL"p
} fc#zhp5bX
} ,1+)qv#|i
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