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)); {R`[kt
} P~X2^bw
for(int i=0;i<nEndPos.length-1;i++) EXqE~afm2
{ }0Ed]
nEndPos = nStartPos[i+1]; l+^*LqEW2
} |&i<bqLw:
nEndPos[nEndPos.length-1] = nFileLength; d/~9&wLSb
} _X x/(.O
} :d'8x
wk_@R=*(\
`VguQl_,gA
//启动子线程 b4N[)%@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7B66]3v
for(int i=0;i<nStartPos.length;i++) '}Z<h?9
{ ' S/gmn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fe_5LC"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3%b6{ie/=
nStartPos,nEndPos,i); LZxNAua
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4BpZJ~(p
fileSplitterFetch.start(); 7HYwLG:\~
} @f3E`8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :Zw2'IV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AH~E)S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R.<g3"Lm>
nEndPos = " + nFileLength); rjnrju+
// fileSplitterFetch[nPos.length-1].start(); e$Pj.>-<=
mQ"-,mMI
pOoEI+t
//等待子线程结束 DZtsy!xA
//int count = 0; _6vWF
//是否结束while循环 dG?*y
boolean breakWhile = false; ]3Sp W{=^(
q'Pf]
=[7Av>
while(!bStop) 8zW2zkv2|#
{ =41?^1\
write_nPos(); =Nr-iae#
Utility.sleep(500); U8$27jq
breakWhile = true; sc#qwQ#
1 [Bk%G@D&
1T n}
for(int i=0;i<nStartPos.length;i++) ?(_08O
{ 'PW5ux@`<
if(!fileSplitterFetch.bDownOver) ")p\q:z6
{ Z6MO^_m2
breakWhile = false; !0<,@v"
break; 44j*KsBf
} yyTnL 2Y9
} ]u/sphPe
if(breakWhile) G7/ +ogV
break; 1<aP92/N&
{Ou1KDy#)
}3WxZv]I}
//count++; 5L}/&^E#p
//if(count>4) W=+ Y|R!
// siteStop(); m+z&Q
} =~LJ3sIX
&m;*<}X
Bdpy:'fJn
System.err.println("文件下载结束！"); l,aay-E
} V0a3<6@4
catch(Exception e){e.printStackTrace ();} aw&,S"A@
} <qt|d&
+R75v)
&_8947
//获得文件长度 T6$+hUM$1
public long getFileSize() Pr C{'XDlU
{ a(ZcmYzXU
int nFileLength = -1; {Qj~M<@3
try{ @BMx!r5kn
URL url = new URL(siteInfoBean.getSSiteURL()); b" [|:F>P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DzRFMYBR
httpConnection.setRequestProperty("User-Agent","NetFox"); {?7Uj
w_VP J
NDokSw-
int responseCode=httpConnection.getResponseCode(); 9%obq/Lb
if(responseCode>=400) \o3gKoL%
{ M X]n&
processErrorCode(responseCode); KwVbbC3
return -2; //-2 represent access is error ?:9"X$XR
} 8zq=N#x
[{/jI\?v
#,'kXj
String sHeader; 4s oJ.j8
*lJxH8\
J]r^W)O
for(int i=1;;i++) ?+8\.a!
{ uCB=u[]y4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;722\y(Y
//Utility.log(in.readLine()); ;-Aa|aT!
sHeader=httpConnection.getHeaderFieldKey(i); +1!ia]
if(sHeader!=null) >+T)#.wo&
{ f* wx<
if(sHeader.equals("Content-Length")) fI|$K)K
{ p5*jzQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b|(:[nB
break; |JsZJ9W+J
} Y}KNKO;
} `kSZX:=};
else &uVnZ@o42
break; RT8 ?7xFc
} 5#z1bu
} ZYNsHcTY
catch(IOException e){e.printStackTrace ();} M D#jj3y
catch(Exception e){e.printStackTrace ();} AQ^u
a$fnh3j[
#T"4RrR
Utility.log(nFileLength); :Llb< MY2
3PF_H$`oJ
V|R,!UND
return nFileLength; \z)%$#I
} B`sAk %
%@Jsal'
MnHNjsO#
//保存下载信息（文件指针位置） ue>D7\8
private void write_nPos() /g.U&oI]D
{ .fs3>@T"#
try{ cidP|ie^
output = new DataOutputStream(new FileOutputStream(tmpFile)); f%8C!W]Dm
output.writeInt(nStartPos.length); y|jq?M<A
for(int i=0;i<nStartPos.length;i++) 8RHUeRX
{ "9807OME
// output.writeLong(nPos); bW:!5"_{H
output.writeLong(fileSplitterFetch.nStartPos); IAyp2
output.writeLong(fileSplitterFetch.nEndPos); MWh6]gGs
} W}ofAkF
output.close(); -tU'yKhn
} ?&uu[y
catch(IOException e){e.printStackTrace ();} Rk8P ax/JK
catch(Exception e){e.printStackTrace ();} NX&_p!_V
} dQG=G%W
\ 6MCxh6
bhs _9ivw
//读取保存的下载信息（文件指针位置） @E8+C8'
private void read_nPos() >.D4co>
{ [_:nHZb
try{ )YI(/*+]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A?0Nm{O;3v
int nCount = input.readInt(); O33`+UV"W
nStartPos = new long[nCount]; &9>vl*
nEndPos = new long[nCount]; 0IWf!Sk ]
for(int i=0;i<nStartPos.length;i++) BL4-7
{ _WbxH
nStartPos = input.readLong(); |V7*l1
nEndPos = input.readLong(); fTX;.M/%
} :fJN->wY^s
input.close(); /Gfw8g\}
} q0\6F^;M
catch(IOException e){e.printStackTrace ();} Zgb!E]V[
catch(Exception e){e.printStackTrace ();} P+HXn8@
} M'l ;:
OB}Ib]
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private void processErrorCode(int nErrorCode) aQI(Y^&%3
{ BLJj(-
System.err.println("Error Code : " + nErrorCode); wS3'?PRX
} a09<!0Rp
H%lVl8oQ
W(/h Vt
//停止文件下载 HLi%%"'
public void siteStop() 7o}J%z
{ CTA3*Gn
bStop = true; (uidNq
for(int i=0;i<nStartPos.length;i++) )=-szJjXZ
fileSplitterFetch.splitterStop(); q" 5(H5
S`]k>' l
a-J.B.A$Z/
} ,v}k{( 16{
} [1H^3g '
//负责部分文件的抓取 -|9=P\U8S
**FileSplitterFetch.java \lNN Msd&
*/ M"To&?OI
package NetFox; -35;j'a
SZCze"`[
II=79$n`G
import java.io.*; PTV:IzoW
import java.net.*; eJ81-!)
f`66h M[
9(<@O%YU
public class FileSplitterFetch extends Thread { z([</D?
mXs; b 2r^
Mrb)
String sURL; //File URL W=4FFl[
long nStartPos; //File Snippet Start Position m~ee/&T
long nEndPos; //File Snippet End Position 1yY0dOoLG)
int nThreadID; //Thread's ID S`Rs82>
boolean bDownOver = false; //Downing is over [=`q>|;pOv
boolean bStop = false; //Stop identical hK|Ul]qI
FileAccessI fileAccessI = null; //File Access interface 8Xs8A.
I1&aM}y{G
MnW+25=N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k$}fWR
{ q-d:TMkc
this.sURL = sURL; Y`wSv NU
this.nStartPos = nStart; 7E!5G2XX~~
this.nEndPos = nEnd; cQ_Hp <D
nThreadID = id; "5$B>S(Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UJ6v(:z<
} eb$#A _m
Nmh*EAJSy
B4 }bVjs
public void run() hehFEyx
{ ^T-V^^#(
while(nStartPos < nEndPos && !bStop) R0-j5&^jju
{ lU8Hd|@-
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a7%]Y}$
try{ |]*/R^1>2
URL url = new URL(sURL); ;i+#fQO7Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8DaL,bi*.
httpConnection.setRequestProperty("User-Agent","NetFox"); uWE^hz"
String sProperty = "bytes="+nStartPos+"-"; lks!w/yCF
httpConnection.setRequestProperty("RANGE",sProperty); SMK_6?MZ
Utility.log(sProperty); e\75:oQ
X)3!_
RViuJ;
InputStream input = httpConnection.getInputStream(); }*"p?L^p{
//logResponseHead(httpConnection); ;gr9/Vl
X!g#T9kG
Uf+%W;}
byte[] b = new byte[1024]; Q&bM\;Ml
int nRead; y"wShAR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pk)1WK7E
{ )w%!{hn
nStartPos += fileAccessI.write(b,0,nRead); R*r#E{!V;
//if(nThreadID == 1) S|+o-[e8O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r]36zX v
} k"w"hg&e
JqiP>4Uwm^
jo@J}`\Zt
Utility.log("Thread " + nThreadID + " is over!"); }RqK84K
bDownOver = true; >[*qf9$
//nPos = fileAccessI.write (b,0,nRead); bA->{OPkT
} GR32S=\
catch(Exception e){e.printStackTrace ();} [!OxZ!
} |ZBI *
} #Mw8^FST
#>+HlT
Y:a]00&)#Y
//打印回应的头信息 H7:] ]j1
public void logResponseHead(HttpURLConnection con) ]OzUGXxo~
{ I,8Er2;)
for(int i=1;;i++) C;urBsC
{ uGlUc<B\*
String header=con.getHeaderFieldKey(i); q'82qY
if(header!=null) HHsmLo c4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P";'jVcR
Utility.log(header+" : "+con.getHeaderField(header)); 0lR5<^B
else s->^=dy
break; MFk5K
} ^gnZ+`3
} L;I]OC^J
IO-Ow!
[ibu/W$
public void splitterStop() ~$?ZK]YOrx
{ M/gGoE{
bStop = true; d>C$+v>
} w`zTR0`
E^eVvP4uC@
ixD)VcD-f
} CzEd8jeh7
sLAQE64\"
oILZgNe'
/* E~oOKQ5W
**FileAccess.java Y0-n\|
*//文件访问(定位，写) @I!0-OjL
package NetFox; )Z9>$V$j
import java.io.*; d-dEQKI?;
N<injx
>\3V a
public class FileAccessI implements Serializable{ Q$Q([Au
,DkNLE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6~w@PRy
RandomAccessFile oSavedFile; N//KPh
long nPos; <GaS36ZW
y_lU=(%Jd
r<^HmpUJ
public FileAccessI() throws IOException B_m8{44zM
{ >I&5j/&}+
this("",0); 81Z) eO#
} ^$hH1H+V
pcWPH.
v^ VitLC
public FileAccessI(String sName,long nPos) throws IOException :G%61x&=Zc
{ $ gS>FJ
oSavedFile = new RandomAccessFile(sName,"rw"); }Kbb4]t|"
this.nPos = nPos; B,epzI
oSavedFile.seek(nPos); v z '&%(
} 0.k7oB;f(@
7%eK37@u
SKsKPqz
public synchronized int write(byte[] b,int nStart,int nLen) wD'SPk5S?
{ Z}Ft:7
int n = -1; W v+?TEP
try{ A{D];pE`
oSavedFile.write(b,nStart,nLen); Fy-t T]Q9
n = nLen; HRfYl,S,
} 2a Q[zK
catch(IOException e) 8c^TT&
{ rCdu0 gYT
e.printStackTrace (); b2&0Hx
} vnZC,J `
RdRp.pb8
[:SWi1cK2
return n; <lE<f+
} ]|PiF+
_^%,x
n]o<S+z
} vT,AMja
3m!X/u
\n|EM@=eE
/* nk's_a*Z
**SiteInfoBean.java sN01rtB(UT
*/ 6zuTQ^pz
package NetFox; ou{2@"
%^1V4
<1${1A <Wa
public class SiteInfoBean { [j/9neaye
N~zdWnSZ@G
0{}8(
private String sSiteURL; //Site's URL aE$[52
private String sFilePath; //Saved File's Path aQ\$A`?
private String sFileName; //Saved File's Name 57
private int nSplitter; //Count of Splited Downloading File [~c|mOk
a'yK~;+_9
SbrecZ
public SiteInfoBean() )W _v:?A9
{//nSplitter的缺省值为5 x\G'kEd
//default value of nSplitter is 5 o9yJf#-En
this("","","",5); dn$!&
} w-L=LWL\
PmEsN&YP]
3kp+<$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }Sh?S]]`
{ mLLDE;7|}
sSiteURL= sURL; V#gK$uv
sFilePath = sPath; gu.}M:u
sFileName = sName; v\%HPMlh
this.nSplitter = nSpiltter; B!L{
rlSeu5X6
< !C)x
} ['tY4$L(
SP_75BJ
ywmo#qYe
public String getSSiteURL() 6HWE~`ok6
{ `%"\@<
return sSiteURL; #r~# I}U
} `%9 uE(
ShP^A"Do
u.m[u)HQ
public void setSSiteURL(String value) Zaf:fsj>
{ Gk&)08
sSiteURL = value; 6wjw^m0
} 1FL~ndJs
2E)-M9ds
,Np0wg0
public String getSFilePath() k|PN0&J
{ fW1CFRHH
return sFilePath; :vQrOn18p
} :zke %Yx
5 ,B_u%bb
i^Y+?Sx
public void setSFilePath(String value) CXx*_@}MU
{ A>;bHf@
sFilePath = value; '"/=f\)u
} !6O(-S2A
.glA gt
;)z:fToh
public String getSFileName() bSi%2Onj
{ VSI9U3t3w
return sFileName; Q%f^)HZGR
} nuMD!qu!nZ
g63(E,;;J
XZ]uUP
public void setSFileName(String value) vDhh>x(
{ +RMSA^
sFileName = value; i0kak`x0
} }t=!(GOb}
A,Vu\3HS
ub#a`
public int getNSplitter() CMG&7(MR
{ }Gm>`cw-
return nSplitter; S8wLmd>
} DIfaVo/"
^]0Pfna+N
:tB1D@Cb6
public void setNSplitter(int nCount) iDz++VNV
{ Sc1 8dC0
nSplitter = nCount; gpvYb7Of0
} kY|utoAP
} H.|#c^I
(Ag16
FF(#]vz'
/* %G/hD
**Utility.java /hH
*/ lH x^D;m6
package NetFox; Rn(ec
s_OF(o
~IfJwBn-i
public class Utility { n&;85IF1
Ms5ap<q#
HIR~"It$
public Utility() bz2ztH9 n
{ i$:*Pb3mV
v6M6>&RR|
Vl/+;6_
} d *|Y o
L~rBAIdD
//线程睡眠 vrhT<+q
public static void sleep(int nSecond) +_?hK{Ib"
{ 8:c-k|CX
try{ ]}-7_n#cC
Thread.sleep(nSecond); ?FeYN+qR
} 7uS~MW
catch(Exception e) 0w\zLU
{ U9:zVy
e.printStackTrace (); ^& tZ
} 9N%We|L,c
} n.`($yR_
h-#6av:
//日志 p$NQyS5C"S
public static void log(String sMsg) hOu3 bA
{ :0j?oY~e
System.err.println(sMsg); ,.83m%i
} LqoB 10Kc\
"3)C'WlEy/
hl7bzKO*w
public static void log(int sMsg) @uqd.Q
{ ?wiCQ6*$
System.err.println(sMsg); |+FubYf?$
} ~q@|l3?$
} 1MP~dRZ$
MSQEO4ge
VgG0VM
/* /og=IF2:
**TestMethod.java W#4 7h7M
*/ @;zl
package NetFox; \=?a/
fNli
\}u Y'F
public class TestMethod { 7 S#J>*
UqFO|r"M
^pAAzr"hv
public TestMethod() <ktrPlNuM
{ ///xx/weblogic60b2_win.exe 53;}Nt#R
try{ xjuN-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d6?j`~[7#-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]_mb7X>
SiteFileFetch fileFetch = new SiteFileFetch(bean); lk^Ol&6
fileFetch.start(); ~:rl=o}
} k$z_:X
catch(Exception e){e.printStackTrace ();} -[4T
G\/zkrxmv
Yh@JXJ>
} _JzEGpeG
n71r_S*
V%7WUq
public static void main(String[] args) knu,"<
{ ?yrX)3hyH
new TestMethod(); w=0(<s2
} =1FRFZI!j
} 1y4|{7bb
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