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)); u%e~a]
} -W1p=od
for(int i=0;i<nEndPos.length-1;i++) YLQ0UeDN'
{ ws5Ue4g|
nEndPos = nStartPos[i+1]; KS93v9|
} 3sdL\
nEndPos[nEndPos.length-1] = nFileLength; {Ba&
} y)&K9 I
} H}5WglV.
vE'{?C=EM
<^Vj1s
//启动子线程 :=;{w~D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }R#W<4:
for(int i=0;i<nStartPos.length;i++) jw=PeT|
{ GnW MI1$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "}qs+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aH{)|?
nStartPos,nEndPos,i); eIalcBY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Yp#`}Ii
fileSplitterFetch.start(); lP`BKc,
} <C&|8@A0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O7VEyQqf5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F""9O6u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $~.YB\3
nEndPos = " + nFileLength); }q@#M8b
// fileSplitterFetch[nPos.length-1].start(); i,*m(C@F}
]<f(@]R/d
C$6FI`J
//等待子线程结束 <A)M^,#o
//int count = 0; *PnO$q@`
//是否结束while循环 B F<u3p??
boolean breakWhile = false; T8z?_ *k
}Cu[x'J
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while(!bStop) UTyV6~
{ !Yb !Au[
write_nPos(); 8i`>],,ch
Utility.sleep(500); $N)G:=M!s
breakWhile = true; zVw5(Tc
kaekH*m~
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for(int i=0;i<nStartPos.length;i++) K#wA ;
{ }psRgF
if(!fileSplitterFetch.bDownOver) e9h@G#
{ s/IsrcfM
breakWhile = false; (8h4\utA
break; c]ARgrH-
} g) u%?T
} Vz/w.%_g
if(breakWhile) 50N4J
break; ~SQxFAto
:Fb>=e
0W*{ 1W
//count++; L/tn;0
//if(count>4) 7amVnR1f
// siteStop(); "g"a-{8
} ,sAAV%">
Uv *Aa7M
nFEJO&1+
System.err.println("文件下载结束！"); &[-(=43@
} xeU|5-d'
catch(Exception e){e.printStackTrace ();} ~%/Rc`
} zg<-%r'$
jn V=giBu
w7U]-MW6A*
//获得文件长度 b/z-W`gw
public long getFileSize() ja_8n["z
{ ]WDmx$"&e
int nFileLength = -1; %Gh5!e:$SI
try{ 6*9wGLE
URL url = new URL(siteInfoBean.getSSiteURL()); tf~B,?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w_56y8Pd4
httpConnection.setRequestProperty("User-Agent","NetFox"); o?Hfxp0}
+;q\7*
AYA{_^#+3
int responseCode=httpConnection.getResponseCode(); ,D+ydr
if(responseCode>=400) !lgL=Ys(
{ #,d~t
processErrorCode(responseCode); ls 5iE
return -2; //-2 represent access is error uPz+*4+
} ;9T}h2^`B
%f1%9YH
>s{I@#9
String sHeader; D9oNYF-V
&ry*~"xoh
neI7VbH4
for(int i=1;;i++) elCYH9W^
{ `uMEK>b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k <oB9J
//Utility.log(in.readLine()); |NfFe*q0;8
sHeader=httpConnection.getHeaderFieldKey(i); ?J\&yJ_B
if(sHeader!=null) }]vUr}Els
{ sW]^YT>?
if(sHeader.equals("Content-Length")) -XV,r<''
{ N*-tBz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {q0+PzgP
break; m;OvOc,
} j~qm$'H
} X,|8Wpi=
else FXof9fa_B
break; N6y9'LGG`
} %F>~2g?$
} ii)#(b:V
catch(IOException e){e.printStackTrace ();} &F&`y
catch(Exception e){e.printStackTrace ();} Ht Fr(g\"$
fc9;ZX7
Ap dXsL
Utility.log(nFileLength); ebk>e*
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return nFileLength; qk(Eyp
} [A-_?#cZ
Nn. 9J
5CkG^9
//保存下载信息（文件指针位置） K~ eak\=
private void write_nPos() !/is+ xp
{ OM\J4"YV$
try{ 2zBk#c+
output = new DataOutputStream(new FileOutputStream(tmpFile)); J6Z[c*W
output.writeInt(nStartPos.length); \]tBwa
for(int i=0;i<nStartPos.length;i++) @k?vbq
{ r6m^~Wq!}
// output.writeLong(nPos); }e[ E
output.writeLong(fileSplitterFetch.nStartPos); ?,vLRq.
output.writeLong(fileSplitterFetch.nEndPos); ?Z#N9Z~\
} OsgPNy0
output.close(); ,"%C.9a
} Z,).)y#B
catch(IOException e){e.printStackTrace ();} /s\ mV
catch(Exception e){e.printStackTrace ();} }T?X6LA$I8
} }Ce9R2
7OV^>"S
hw DxGiU
//读取保存的下载信息（文件指针位置） fq7#rZCxX
private void read_nPos() B5lwQp]
{ <XdnVe1
try{ INg0[Lpc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sU_K^=6*
int nCount = input.readInt(); 5PeS/%uT@
nStartPos = new long[nCount]; ;,4*uU'vq
nEndPos = new long[nCount]; }%< ?]
for(int i=0;i<nStartPos.length;i++) /7AHd ;
{ BPY7O
nStartPos = input.readLong(); ;KL7SM%g4
nEndPos = input.readLong(); D#g-mqar:
} E'QAsU8pP
input.close(); ;vH2r~
} 0]DOiA
catch(IOException e){e.printStackTrace ();} #dauXUKH
catch(Exception e){e.printStackTrace ();} kuEXNi1l
} `a83RX_\
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4>gfLK\R:
private void processErrorCode(int nErrorCode) 37U8<
{ ]>n{~4a
System.err.println("Error Code : " + nErrorCode); (t4i&7-
} [?]N GTr#
7H7 Xbi@
O<m46mwM
//停止文件下载 @kYY1mv;
public void siteStop() |9E:S
{ 8em'7hR9
bStop = true; TDh)}Ms
for(int i=0;i<nStartPos.length;i++) +IdM|4$\1
fileSplitterFetch.splitterStop(); q)q3p
xWLvx'8W
CNB weM
} N1t4o~
} )&c2+Y@
//负责部分文件的抓取 c2E /-n4K@
**FileSplitterFetch.java VI! \+A
*/ -KiPqE%&G
package NetFox; 9[eiN
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import java.io.*; -X.#Y6(
import java.net.*; 14,)JZN
UTA|Ps$
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public class FileSplitterFetch extends Thread { H=/1d.p
1-kuK<KR
V3,C5KKk&z
String sURL; //File URL 9jal D X
long nStartPos; //File Snippet Start Position Ia2WBs=
long nEndPos; //File Snippet End Position e{)giJY9
int nThreadID; //Thread's ID z|g2Q#$-\S
boolean bDownOver = false; //Downing is over |~9rak,
boolean bStop = false; //Stop identical M Kyj<@[
FileAccessI fileAccessI = null; //File Access interface \8{SQ%
]cRvdUGv
zEQ]5>mG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iJ>=!Q
{ +t7HlAXB#
this.sURL = sURL; YU,zQ V'
this.nStartPos = nStart; {j wv+6]U
this.nEndPos = nEnd; N8sT?
nThreadID = id; [L%Ltmx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ']}-;m\
} Tuvs}
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public void run() 4H8r[
{ (Jq m9
while(nStartPos < nEndPos && !bStop) 0#|Jhmv-zL
{ Q2fxsa[
t>[QW`EeP
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try{ z~H1f$}
URL url = new URL(sURL); 5hE#y]pfN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~kc#"^sJ
httpConnection.setRequestProperty("User-Agent","NetFox"); 1jC85^1Taq
String sProperty = "bytes="+nStartPos+"-"; 5gz^3R|`f
httpConnection.setRequestProperty("RANGE",sProperty); zw<<st Bp
Utility.log(sProperty); uP9b^LEoN
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h,[L6-n
InputStream input = httpConnection.getInputStream(); z%}"=
//logResponseHead(httpConnection); o$@/@r
`I7s|9-=
XT^=v6^H
byte[] b = new byte[1024]; +w0Wg.4V
int nRead; Ana[>wSZO@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -@AhJY.
{ F}Zg3#
nStartPos += fileAccessI.write(b,0,nRead); =Uk#7U"P
//if(nThreadID == 1) ra~=i|s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >MYxj}I4{z
} f1NHW|_j
rfDGS%!O%
dv. 77q
Utility.log("Thread " + nThreadID + " is over!"); TOiLv.Dor
bDownOver = true; {aE[h[=r
//nPos = fileAccessI.write (b,0,nRead); u6C_*i{2
} b^R:q7ea
catch(Exception e){e.printStackTrace ();} fRNj *bIV
} BB}WfA
} t[|rp&xG
ivo3pibk%
2I:P}!
//打印回应的头信息 LJrH_h8C
public void logResponseHead(HttpURLConnection con) 0+mR y57
{ 9fp"r,aHN&
for(int i=1;;i++) jdG'sITv
{ J{/hc} $
String header=con.getHeaderFieldKey(i); \Fjasz5E'
if(header!=null) 1c,#`\Iikd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gwB,*.z
Utility.log(header+" : "+con.getHeaderField(header)); MJX ny4n
else %)V=)l.j
break; ]Zb9F[
} yBK$2to~
} WrP+n
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%LnLB
public void splitterStop() hw"2'{"II
{ /5 z+N(RFC
bStop = true; GUL~k@:_k
} WD4"ft
^Zl[#:EFP
/CALXwL
} YusmMsN?
MTt8O+J?P~
vU *: M8k
/* x|Uwk=;X|s
**FileAccess.java )d[n-Si
*//文件访问(定位，写) jP+{2)z"W
package NetFox; *6JA&zj0B
import java.io.*; @ 2hGkJ-
shB3[W{}!)
n\9IRuYO
public class FileAccessI implements Serializable{ l_k:OZ
XY)X-K$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q'U!
RandomAccessFile oSavedFile; a[;L+
long nPos; N5 sR
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pI f6RwH}%
public FileAccessI() throws IOException T Tbe{nb
{ U/FysN_N!
this("",0); 54{E&QvL8o
} UR'v;V&Cb\
koB'Zp/FaY
*v#V%_o
public FileAccessI(String sName,long nPos) throws IOException RAa1^Qb
{ TT3 6Y
oSavedFile = new RandomAccessFile(sName,"rw"); bV:<%l]
this.nPos = nPos; Jd `Qa+
oSavedFile.seek(nPos); U:x;4
} NxJnU<g-
h_-4Q"fb(
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public synchronized int write(byte[] b,int nStart,int nLen) S/Ic=
{ ebEI%8p g
int n = -1; .3) 27Cjw
try{ \e'Vsy>q
oSavedFile.write(b,nStart,nLen); (Jb#'(~a
n = nLen; +Zi+ /9Z(H
} )Q9Qo)D T
catch(IOException e) = y^5PjN
{ o(}%b8 K
e.printStackTrace (); !Th5x2
} &qY]W=9uK
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1q=Q/L4P
return n; z}}P+P/
} "+2Cs
,e|"p[z~T
B0 A`@9
} 7"Nda3
^EN )}:%Z
0"j:-1
/* ^$dbyj`
**SiteInfoBean.java ElTB{C>u
*/ 7Wv.-LD6
package NetFox; ] 0L=+=w
ZweAY.]e
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public class SiteInfoBean { &I-T
VZ IY=Q>g
=x?WZMO
private String sSiteURL; //Site's URL ;d>n2
private String sFilePath; //Saved File's Path iN[6}V6Sm
private String sFileName; //Saved File's Name K:9AP{+
private int nSplitter; //Count of Splited Downloading File IkmEctAU
k|>yFc
q'trd};xR
public SiteInfoBean() M_+W5Gz<
{//nSplitter的缺省值为5 byP<!p*
//default value of nSplitter is 5 )Vy0V=
this("","","",5); k:7Gb7\
} a:GM|X
Qm7];,
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?zP 2
{ t+d7{&B
sSiteURL= sURL; [&P@0Fn
sFilePath = sPath; vaQsG6q[
sFileName = sName; rF}Q(<Y86
this.nSplitter = nSpiltter; U<F|A!Fg
6.tA$#6HP
feS$)H9-
} % u VTf
e[Vk+Te7
gT+wn-3
public String getSSiteURL() 0datzEns`
{ #:[F=2@,A
return sSiteURL; y(iq
} ->OVNmCB`+
nT01B1/<]
%hmRh~/&
public void setSSiteURL(String value) &=S:I!9;;
{ `, ]ui*
sSiteURL = value; 1D)0\#><
} hMz)l\0
&2.DZ),L
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public String getSFilePath() IP{$lC
{ D=%1?8K
return sFilePath; ^uG^>Om*
} ]Ue aXwaU
IDf\!QGx
}'}n~cA.{
public void setSFilePath(String value) %${$P+a`D
{ /Q)I5sL@E
sFilePath = value; `<~=6H
} 4P5^.\.
vP#*if[V5
B R
public String getSFileName() 4 7mT
{ }8YY8|]LI
return sFileName; /~".GZ&29
} <-' !I&
s8's(*]
)2l @%?9
public void setSFileName(String value) Yj bp:
{ {7DXSe4
sFileName = value; a-S tOO5s
} IIT[^_g
6`6 / 2C$%
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public int getNSplitter() i?b9zn
{ b{aB^a:f=L
return nSplitter; 04}8x[t
} )\D{5j
2[(~_VJ
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public void setNSplitter(int nCount) 2?6]Xbs{
{ xR kw+
nSplitter = nCount; j `!Ge
} nhMxw@Z\
} xDl; tFI
/TPtPq<7:#
N.q*jY=X|
/* k18v{)i~
**Utility.java JF~9efWe>
*/ p/nATvh$
package NetFox; o o'7
|/xx**?
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public class Utility { U/AiI;Ne
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_x""-X~OL
public Utility() sG_/E-%5'
{ }6.@
Ua:@,};
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} sCt)Yp+8}B
<FU?^*~
//线程睡眠 <)!,$]S
public static void sleep(int nSecond) R ai 04
{ +C~d;p
try{ (p12=EB<
Thread.sleep(nSecond); p[xGL } +\
} FP=27=
catch(Exception e) L~;(M6Jp
{ rOE: ap|KL
e.printStackTrace (); *k8?$(
} 6@8t>"}
} O<V 4j,
%1jcY0zEQ
//日志 >P@VD"U
public static void log(String sMsg) T^`; wD
{ li\=mH,Wr
System.err.println(sMsg); JrY*K|YdW
} 9)W &yi
-3)jUzD
[|c%<|d2
public static void log(int sMsg) j-R*!i
{ y2jw3R
System.err.println(sMsg); 3TCRCz
} Ic_NQ<8
} >l AtfN='
w$9LcN
2YKa <?_
/* &qdhxc4
**TestMethod.java A&Aj!#
*/ 0mUVa=)D
package NetFox; g;p} -=
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public class TestMethod { /u.ZvY3,
3BCD0 %8
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public TestMethod() _ pz}
{ ///xx/weblogic60b2_win.exe DZC@^k \E
try{ <]1,L%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wz69Yw7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3Y2~HuM
SiteFileFetch fileFetch = new SiteFileFetch(bean); <C(o0u&/
fileFetch.start(); OHpV%8`
} B T"R"w
catch(Exception e){e.printStackTrace ();} +ppA..1
a=j'G]=
lD3nz<p
} 37jxl+
:p: C
{LF4_9 =
public static void main(String[] args) CKK}Z;~:
{ ]r|oNGD)G
new TestMethod(); :[_msd
} $+7uB-KsU
} '-RacNY
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