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)); 2F.;;Ab
} @,+5y\]C
for(int i=0;i<nEndPos.length-1;i++) ]%H`_8<gc
{ hn@08t G
nEndPos = nStartPos[i+1]; q<|AZ2Ai
} .`eN8Dl1
nEndPos[nEndPos.length-1] = nFileLength; FVKTbvYn
} + &Eqk
} +O{*M9B
X+9>A.92
b8UO,fY q
//启动子线程 M6jy\<a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {VRf0c
for(int i=0;i<nStartPos.length;i++) g!|kp?
{ ;)*eo_tQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #;e:A8IQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gwMNYMI
nStartPos,nEndPos,i); 1Pu~X \sO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;A*]l'[-
fileSplitterFetch.start(); Jnov<+
} 4D4j7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g) jYFfGfH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^09,"<@k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wc4=VC"y
nEndPos = " + nFileLength); DvvK^+-~
// fileSplitterFetch[nPos.length-1].start(); #*Ctwl,T
f ;n3&e0eC
~c `l@:
//等待子线程结束 sO@Tf\d
//int count = 0; g($2Dk_F2
//是否结束while循环 O\r0bUPE
boolean breakWhile = false; z Iu'[U
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rx|pOz,:
while(!bStop) XSLFPTDEc
{ 'H;*W|:-]
write_nPos(); z2GY:<s
Utility.sleep(500); '`Hr}
breakWhile = true; Dlvz)
#ABZ&Z
ww1[rCh\+
for(int i=0;i<nStartPos.length;i++) 7%M_'P4 V
{ OneY_<*a<
if(!fileSplitterFetch.bDownOver) FYQS)s
{ vFmZ<C' )
breakWhile = false; ]Y&VT7+Z
break; &oMh]Z*:
} f/?P514h
} ZN0P:==
if(breakWhile) Z%UP6%
break; pQB."[n
xAm6BB c
@6-jgw>W2
//count++; [$UI8tV
//if(count>4) }Q+|W=2t
// siteStop(); A04U /;
} @=u3ZVD
vl)l'
OY({.uVdX
System.err.println("文件下载结束！"); j?QDR
} owv[M6lbD
catch(Exception e){e.printStackTrace ();} F!K>Kz
} e*1_8I#2
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S+lqA-:
//获得文件长度 6Kz,{F@
public long getFileSize() tZo} ;|~'
{ \|[;Z"4l
int nFileLength = -1; GC'O[q+
try{ qqU 64E
URL url = new URL(siteInfoBean.getSSiteURL()); _@/8gPT*i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a8Wwq?@
httpConnection.setRequestProperty("User-Agent","NetFox"); ]]yO1x$Kk
8q7b_Pq1U
lu/ (4ED
int responseCode=httpConnection.getResponseCode(); L}NSR
if(responseCode>=400) =2x^nW
{ QS`]
processErrorCode(responseCode); Z3!`J&
return -2; //-2 represent access is error T51 `oZ`
} tq?!-x+>
kG*~|ma
kU`r)=1"
String sHeader; +ck}l2&#
P0b7S'a4!
%8x#rohP
for(int i=1;;i++) >LuYHr
{ B>.qd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z/J y'$x
//Utility.log(in.readLine()); k VQ\1!
sHeader=httpConnection.getHeaderFieldKey(i); nQS|Lt_+
if(sHeader!=null) rVsJ`+L
{ Z%\,w(o[h
if(sHeader.equals("Content-Length")) vr^qWn
{ 40 0#v|b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lw5`p,`
break; 1-QS~)+
} WuW^GC{7
} ;A!BVq
else @s^-.z
break; 8dyg1F
} " 2Dngw
} mj@13$=
catch(IOException e){e.printStackTrace ();} VLN_w$iEq
catch(Exception e){e.printStackTrace ();} gPc=2
>lM l
8HdAFRw
Utility.log(nFileLength); 1ZRT:N<-
sn>~O4"
6S\8$
return nFileLength; >@AB<$A
} #cLBQJq
61 ~upQaR
yR.Ong
//保存下载信息（文件指针位置） dAe')N:KPI
private void write_nPos() 4nz35BLr
{ T9q-,w/j;
try{ ua `RJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); &]-DqK7
output.writeInt(nStartPos.length); & "B=/-(
for(int i=0;i<nStartPos.length;i++) dGTsc/$
{ 0Fr?^3h
// output.writeLong(nPos); K'I#W lg
output.writeLong(fileSplitterFetch.nStartPos); Q)z8PQl O
output.writeLong(fileSplitterFetch.nEndPos); uA#;G/$
} RY*U"G0#w
output.close(); #yvGK:F
} ,3 u}x,
catch(IOException e){e.printStackTrace ();} ?@ $r
catch(Exception e){e.printStackTrace ();} 9@)O_@=
} ;P&OX5~V
{T~#?v(
eGbGw
//读取保存的下载信息（文件指针位置） 9k[9P;"F:
private void read_nPos() r-/`"j{O!
{ W'u>#
try{ 01(AK%e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xFg>SJ7]
int nCount = input.readInt(); iMRwp+$
nStartPos = new long[nCount]; 4|#WFLo@
nEndPos = new long[nCount]; Nu~lsWyRI5
for(int i=0;i<nStartPos.length;i++) &Z|P2dI
{ TrR8?-
nStartPos = input.readLong(); n>U5R_T
nEndPos = input.readLong(); sds"%]rg
} H~z`]5CN
input.close(); KRKCD4
} QUQ'3
catch(IOException e){e.printStackTrace ();} "`1bA"E
catch(Exception e){e.printStackTrace ();} #@nezu2
} 2Q:+_v
Fh9h,' V"
^@NU}S):yN
private void processErrorCode(int nErrorCode) )B8$<sv
{ x.R4%Z
System.err.println("Error Code : " + nErrorCode); .y:U&Rw4
} jsi!fx2Rm
>!)DM]Ri
OJy#w{4
//停止文件下载 cD'V>[h
public void siteStop() YLn?.sV{[0
{ n#_$\ p>Yd
bStop = true; -v|qZ'
for(int i=0;i<nStartPos.length;i++) v^+Sh|z/
fileSplitterFetch.splitterStop(); G+\GaY[
Y,zxbXZv'5
Gjo`&#
} h>OfOx/{q9
} <B8!.|19
//负责部分文件的抓取 0}quG^%_
**FileSplitterFetch.java e'D&8z_;
*/ dL )<% o
package NetFox; b(O3@Q6[
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V[vl!XM
import java.io.*; (;^syJrh
import java.net.*; #],&>n7'
pr UM-u8
:1KpGj*F
public class FileSplitterFetch extends Thread { (mtk 4
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!5uGd`^I
String sURL; //File URL 9\JF`ff_
long nStartPos; //File Snippet Start Position HBx=\%;n
long nEndPos; //File Snippet End Position `XEr(e9
int nThreadID; //Thread's ID 6MdiY1Lr!K
boolean bDownOver = false; //Downing is over _X"N1,0
boolean bStop = false; //Stop identical ,f;}|d:r
FileAccessI fileAccessI = null; //File Access interface WWHoi{q
_8UDT^?8,
k-OPU,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]G< Vg5
{ Is?La
this.sURL = sURL; Q9G;V]./
this.nStartPos = nStart; [!]2djc
this.nEndPos = nEnd; ^iw'^6~
nThreadID = id; 2n"V}p>8i#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _?0}<kQ&
} g0ly
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k4y'b
public void run() KE3;V2Ym f
{ CDR@ `1-
while(nStartPos < nEndPos && !bStop) Oh6fj}eK
{ $F+ LDs
HLaRGN3,
p/@smke
try{ K':;%~I
URL url = new URL(sURL); o;<Xo&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yx&51G$
httpConnection.setRequestProperty("User-Agent","NetFox"); /F'sb[
String sProperty = "bytes="+nStartPos+"-"; 1rF]yi:X
httpConnection.setRequestProperty("RANGE",sProperty); wLJ:\_Jaf
Utility.log(sProperty); "v({,
MC:@U~}6
OCaq3_#tZ
InputStream input = httpConnection.getInputStream(); @wo(tf=@P
//logResponseHead(httpConnection); c*L\_Vx+
k:F9. j%*
e-#BDN(O
byte[] b = new byte[1024]; =wOm}V8N&
int nRead; [dIXR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bU:EqW\(^
{ =sJ7=39
nStartPos += fileAccessI.write(b,0,nRead); 6'G6<8>-
//if(nThreadID == 1) 22M1j5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8sM|%<$=j
} 27O|).yKX
MWpQ^dL_
cacr=iX
Utility.log("Thread " + nThreadID + " is over!"); p=GBUII #
bDownOver = true; yiC^aY=-
//nPos = fileAccessI.write (b,0,nRead); b Y\K
} yvHA7eq*"
catch(Exception e){e.printStackTrace ();} mmEYup(l0;
} h!.^?NF
} vMt/u?oB
:f}9($
fS[,vPl
//打印回应的头信息 Hmd] FC,_
public void logResponseHead(HttpURLConnection con) dDGgvi|[Mz
{ lG!|{z7+0
for(int i=1;;i++) {kCw+eXn?
{ MLje4
String header=con.getHeaderFieldKey(i); XJ` ]ga
if(header!=null) 4Thn])%I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uU <=d
Utility.log(header+" : "+con.getHeaderField(header)); n%C>E.Tq
else M&@b><B
break; Vp*KfS]
} )Sg~[WxDv
} Q<'nE
"UGY2skf;
P&)xz7wG
public void splitterStop() q[`]D7W "
{ (k) l=]`}
bStop = true; 1[qLA!+
} o( RG-$
=K{"{5Wb
L,`Lggq-
} }Q?c"H!/
6@e+C;j=
D 38$`j
/* KJ=6n%6
**FileAccess.java 6c"0})p
*//文件访问(定位，写) i2YuOV!
package NetFox; V|/NB
import java.io.*; #Jn_c0
V\6[}J
8x8uo
public class FileAccessI implements Serializable{ 8XzR wYV
KgOqbSJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W?aI|U1
RandomAccessFile oSavedFile; s3O} 6
long nPos; oA7;.:3
{u\Mj
7,|c
public FileAccessI() throws IOException t!x5fNo)
{ 'fF;(?
this("",0); _$f9]bab
} >`wV1^M6?
*R3f{/DK
aj}sc/Qa
public FileAccessI(String sName,long nPos) throws IOException ;A'Z4=*~
{ AvSM^
oSavedFile = new RandomAccessFile(sName,"rw"); jhu&&==\f
this.nPos = nPos; ?)[EO(D
oSavedFile.seek(nPos); \X&H;xnC5
} {>,V\J0p
1Q4}'0U4
s]mY*@a%
public synchronized int write(byte[] b,int nStart,int nLen) N:tY":Hi
{ \ZhfgE8{%
int n = -1; x{,q]u /
try{ UIAj]
oSavedFile.write(b,nStart,nLen); <Ib[82PU
n = nLen; [],1lRYI9_
} AfP'EP0m
catch(IOException e) MpqZH{:?G
{ ivz>dJ?T
e.printStackTrace (); 'd&0Js$^
} .E&z$N
|t)}VM%
f7~9|w&
return n; lGk{LO)
} nF4a-H&Fo
qY$qaM^=
M=*bh5t%]
} qc!MG_{Y
7aYn0_NKp
{W~q z^>u4
/* _s$_Sa ;
**SiteInfoBean.java B Ma)O
*/ drd/jH&
package NetFox; +:-57
>,gvb5
N0w`!<y:c
public class SiteInfoBean { iQ6epg1wB
V0(o~w/W%!
qdG~!h7j
private String sSiteURL; //Site's URL |?,[@z _,
private String sFilePath; //Saved File's Path kWb2F7m
private String sFileName; //Saved File's Name k@D0 {z
private int nSplitter; //Count of Splited Downloading File 8W+gl=C~
d:q +
F3lw@b3])
public SiteInfoBean() IU]^&e9u
{//nSplitter的缺省值为5 pdb1GDl0q
//default value of nSplitter is 5 Enq|Y$qm
this("","","",5); a7/-wk
} =!UR=Hq
H:JLAK
70Yjv1i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ow;R$5G
{ BH@)QVs-
sSiteURL= sURL; -/dEsgO
sFilePath = sPath; #4h+j%y[H
sFileName = sName; (zYy}g#n
this.nSplitter = nSpiltter; n*'<uKpM
GOB(#vu
#W2[
} Q U F$@)A
desThnTw
_uu<4c
public String getSSiteURL() !b-bP,q
{ NOK/<_/
return sSiteURL; zggB$5
} }2r+%V&4
`}no9$l~
a>B[5I5
public void setSSiteURL(String value) _0 snAt^iC
{ y8bM<e2 U
sSiteURL = value; X0+fsf<H}
} &MgeYpd
oXt,e
X7|.T0{=x
public String getSFilePath() 5lJ)(|_
{ w*w?S
return sFilePath; '!Kf#@';u
} cQZ652F9
-,":5V26
=S]a&*M
public void setSFilePath(String value) \Z-2leL)j
{ qturd7
sFilePath = value; b}zBn8l
} Zq ot{s
oeL5}U6>g
/=#~
public String getSFileName() x@cN3O
{ Lg`Jp&Kg
return sFileName; xQlT%X;'
} g>7Y~_}
=ziy`#fm,
(%Oe_*e}Y
public void setSFileName(String value) K2/E#}/
{ jlKGXD)Q[
sFileName = value; HrqF![_
} .1*DR]^`
02]xJo
$)e:8jS=
public int getNSplitter() s"0b%0?A
{ ~j,TVY
return nSplitter; CYB=Uq,
} ? Ekq6uz\)
A@$fb}CF
Zy wK/D
public void setNSplitter(int nCount) U?U(;nSR\A
{ ]u&dJL
nSplitter = nCount; A1,4kqmE
} K ar~I
} -%uy63LbHF
^w6eWzI
<~%t$:
/* 9Nl*4
**Utility.java +|nsu4t,<
*/ 9|K*G~J
package NetFox; Jc~E"x
q?VVYZXP
/.Wc_/
public class Utility { lfMH1llx
2_olT_#
$ WFhBak8
public Utility() AZ8UXq
{ C/+nSe.
rr>~WjZ3
!=M/j}
} _XN~@5elrC
.D@/y uV
//线程睡眠 >1XL;)IL>
public static void sleep(int nSecond) RUrymkHFB
{ iy 3DX|]
try{ x[m'FsR4
Thread.sleep(nSecond); @dhH;gt.I
} 3GWrn,f
catch(Exception e) p[P[#IeL
{ aT/KT,!
e.printStackTrace (); &kq7gCd
} pFH?/D/q
} bVmvjY4
`1p?*9Ssn
//日志 kOM-
public static void log(String sMsg) B=x~L
{ >\-3P$
System.err.println(sMsg); XkoWL
} Y=WR6!{
0- Yeu5A
bfc.rZ
public static void log(int sMsg) \1khyF'
{ +wjlAqMQ
System.err.println(sMsg); NFM-)Z57
} _9qEZV
} 0kz7 >v
=tP$re";o
?ZM^%]/+
/* !Ba3`B5l
**TestMethod.java ;op'V6iG
*/ JbVi1?c
package NetFox; <e^6.!;W
n%8#?GC`
iqlVlm>E
public class TestMethod { [@s=J)H
O^Dc&w
/T4VJ{D
public TestMethod() i&B?4J)
{ ///xx/weblogic60b2_win.exe Dl@{}9
try{ A<1l^%i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /TG| B Eb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f@#w{W,3
SiteFileFetch fileFetch = new SiteFileFetch(bean); f>b!-|
fileFetch.start(); ]s}aC9I
} sF, uIr/
catch(Exception e){e.printStackTrace ();} L)=8mF.
O\:;q*]
A1Ibx|K
} S@;&U1@h
1_XO3P\
P|yGx)'^P
public static void main(String[] args) Ty(yh(oYF`
{ C!oksI
new TestMethod(); Udg& eEF
} t PAt?
} o7hH9iY
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