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)); hFLD2<
} F 7v 1rf]
for(int i=0;i<nEndPos.length-1;i++) oP[R?zN
{ XsOz {?G
nEndPos = nStartPos[i+1]; d7g3VF<j
} GJpQcse%
nEndPos[nEndPos.length-1] = nFileLength; ]@Gw$
} #0;H'GO?c
} ;|C[.0;kgv
Sbf+;:D
UEm~5,>$0
//启动子线程 -w>2!@8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;M)l7f
for(int i=0;i<nStartPos.length;i++) Qyh_o
{ VLLE0W _]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d&N[\5q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rMV<}C ^
nStartPos,nEndPos,i); 3Ryae/Nk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #2dd`F8
fileSplitterFetch.start(); |.asg
} o@o0V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V_1'` F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zO@7V>2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .ty^k@J|]
nEndPos = " + nFileLength); pn5A6 #
// fileSplitterFetch[nPos.length-1].start(); Mg7nv\6
F.N4Q'2Z
N;\G=q] 9
//等待子线程结束 8y9`xRy
//int count = 0; Cob<N'.
//是否结束while循环 #b^x!lR
boolean breakWhile = false; 7v{X?86&
zB/)_AW
N:4oVi@Je
while(!bStop) P#gY-k&Nr
{ TbK;_pg
write_nPos(); [{K
Utility.sleep(500); ( E8(np
breakWhile = true; Ym]Dlz,o
e*nT+Rp
[ X7LV
for(int i=0;i<nStartPos.length;i++) +{eZ@
{ cH==OM7&-
if(!fileSplitterFetch.bDownOver) KNI* :
{ GnCO{"n
breakWhile = false; ])v,zp"u
break; LTof$4s
} ].A>ORS/
} != @U~X|cu
if(breakWhile) -GqMis}c
break; D'nO
[@"7qKd1
4E"OD+
//count++; J|'e.1v
//if(count>4) bwr}Ge
// siteStop(); &,4 3&pFU
} 6Cdc?#&
1vy*u
~F{u4p7{N
System.err.println("文件下载结束！"); /:<.Cn>-
} h2Kx
catch(Exception e){e.printStackTrace ();} RyAss0Sm^
} K6 {0`'x
y4^w8'%MC
| e&v;48
//获得文件长度 =Wgz\uGJ
public long getFileSize() 31FQ=(K
{ #iZ%CY\
int nFileLength = -1; ^Z6N&s#6
try{ ! u4'1jd[d
URL url = new URL(siteInfoBean.getSSiteURL()); C>A*L4c]F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JQ[~N-
httpConnection.setRequestProperty("User-Agent","NetFox"); @P$_2IU"
f^EDiG>b`
z 8w&;Ls
int responseCode=httpConnection.getResponseCode(); =m+'orJ1
if(responseCode>=400) /q3]AVV
{ eM>f#M
processErrorCode(responseCode); #]vy`rv
return -2; //-2 represent access is error !)nA4l=S#
} :(^,WOf
H&yK{0H
ec$kcD!
String sHeader; C0Oe$& _
h_SDW %($
D:r+3w:l]
for(int i=1;;i++) 6)@Y41H]C
{ &+K:pU?[$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~EV7E F
//Utility.log(in.readLine()); 0/vmj,&B(
sHeader=httpConnection.getHeaderFieldKey(i); 7,pn0,HI
if(sHeader!=null) P ~sX S
{ $@wTc
if(sHeader.equals("Content-Length")) o1dECLQa
{ C2Pw;iK_t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J7p'_\
break; pOe"S
} j;3hQOl
} )`*=P}D
else u>YC4&
break; Cq<a|t
} a$7}41F[~s
} 9:]w|lE:D
catch(IOException e){e.printStackTrace ();} ZQ0R3=52r
catch(Exception e){e.printStackTrace ();} App9um3:
Kgb3>r
e*zt;SR
Utility.log(nFileLength); |k3^ eeLk
`<3/k
@77%15_Jz
return nFileLength; V>Zw" #Q
} 7Zf *T
4dd]Ju
jMH=lQ+8
//保存下载信息（文件指针位置） "< c,I=A
private void write_nPos() UE-+P
{ i8kyYMPP
try{ aj$#8l |zu
output = new DataOutputStream(new FileOutputStream(tmpFile)); >=WlrmI
output.writeInt(nStartPos.length); {p70( ]v
for(int i=0;i<nStartPos.length;i++) <z=d5g{n
{ 7FTf8
// output.writeLong(nPos); oaK&!$S]
output.writeLong(fileSplitterFetch.nStartPos); v&8%t 7|
output.writeLong(fileSplitterFetch.nEndPos); -9f> rH\3
} I'qIc?
output.close(); TsvF~Gdp
} >@mvb@4*
catch(IOException e){e.printStackTrace ();} DO^K8~]
catch(Exception e){e.printStackTrace ();} $?e_l
} +@j@#~=K
JF+E.-fy$
)[c@5zy~*
//读取保存的下载信息（文件指针位置） ^e1Ux
private void read_nPos() w<0F-0:8
{ :B(vk3;U!
try{ \'BA}v &/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "SV#e4C.
int nCount = input.readInt(); zFq8xw
nStartPos = new long[nCount]; Hl3%+f
nEndPos = new long[nCount]; B9&$sTAB
for(int i=0;i<nStartPos.length;i++) q0>@!1Wb
{ +W8L^Wl
nStartPos = input.readLong(); %#zqZ|q
nEndPos = input.readLong(); UP})j.z
} cGE,3dsF[
input.close(); 4$wn8!x2|
} 3O'6 Ae
catch(IOException e){e.printStackTrace ();} )Gu:eYp+`
catch(Exception e){e.printStackTrace ();} 5g$]ou
} }%@q; "9`
8}^R jMgI
):c)$$dn
private void processErrorCode(int nErrorCode) 9Sy|:J0
{ (sfy14>\
System.err.println("Error Code : " + nErrorCode); -!C9x?gNY
} V*C%r:5 ,v
5N_w(B
zD9gE
//停止文件下载 $r'PYGn
public void siteStop() <uYeev%
{ Y]33:c_;Mo
bStop = true; ^qro0]"LD
for(int i=0;i<nStartPos.length;i++) p:/#nmC<
fileSplitterFetch.splitterStop(); !L=RhMI
+'@j~\>^yJ
nc.(bb),
} 2jUEL=+Y
} FD+y?UF
//负责部分文件的抓取 \?VNr2
**FileSplitterFetch.java .:nV^+)
*/ C~r(*nr
package NetFox; A.%MrgOOX
TGxmc37?
,*r}23
import java.io.*; fGz++;b<S
import java.net.*; :9O"?FE
`/4R$E{
&>T7]])
public class FileSplitterFetch extends Thread { dYn<L/#
*wd@YMOP
G""L1?
String sURL; //File URL ALOS>Bi&
long nStartPos; //File Snippet Start Position icw (y(W
long nEndPos; //File Snippet End Position e-`=?tct
int nThreadID; //Thread's ID Pcs62aE
boolean bDownOver = false; //Downing is over @N%/v*
boolean bStop = false; //Stop identical '@WpJ{]A
FileAccessI fileAccessI = null; //File Access interface 'PBuf:9lN
z K+C&X
I/HcIBJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jMP!/t :w
{ uYu/0fQD
this.sURL = sURL; c2,;t)%@E
this.nStartPos = nStart; KIeTZVu$%
this.nEndPos = nEnd; @|i f^
nThreadID = id; 0YApaL+jt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ny6 daf3f
} P>wDr`*
/KCJ)0UU
"{lw;AA5F
public void run() 3%NbT
{ (=/%_jj
while(nStartPos < nEndPos && !bStop) }R\9ybv
{ l?rT_uO4
*Bj7\8cKC
nB+UxU@
try{ 97]$*&fH
URL url = new URL(sURL); Tx|}ke~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jlA?JB
httpConnection.setRequestProperty("User-Agent","NetFox"); @}r2xY1
String sProperty = "bytes="+nStartPos+"-"; 8e:\T.)M
httpConnection.setRequestProperty("RANGE",sProperty); _Dv<
Utility.log(sProperty); M#U#I:z%
e]qbh_A
5'mpd
InputStream input = httpConnection.getInputStream(); bY>JLRQJ-
//logResponseHead(httpConnection); c@ea ;Cv
pp!>:%
1/l;4~p7'
byte[] b = new byte[1024]; B4>kx#LR
int nRead; c'LDHh7b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s.8]qQRr
{ ;#>,eD2u
nStartPos += fileAccessI.write(b,0,nRead); f]*_]J/
//if(nThreadID == 1) qtQB}r8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^-Knx!z
} K5ywO8_6`
3SU:Xd(\o
y=H\Z/=
Utility.log("Thread " + nThreadID + " is over!"); B\ITXmd
bDownOver = true; @[vwqPOL
//nPos = fileAccessI.write (b,0,nRead); VZRM=;V
} O6Gg?j
catch(Exception e){e.printStackTrace ();} mH/$_x)o
} `~.0PnHf
} UyWKE<
aV6l"A]
M10u?
//打印回应的头信息 0nDlqy6b1b
public void logResponseHead(HttpURLConnection con) JBCJVWUt
{ {;kH&Pp
for(int i=1;;i++) :AzP3~BI
{ F:P&hK
String header=con.getHeaderFieldKey(i); +~H mPQ
if(header!=null) ' >F_y t9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 82q_"y>6
Utility.log(header+" : "+con.getHeaderField(header)); F[65)"^
else }$zJdf,\
break; "V>7u{T
} j+E[[
} AVx 0aj
-H;%1y$A-
c[DC
public void splitterStop() -nvK*rn>}
{ G|"`kAa
bStop = true; [p%OIqC`pB
} oV7A"8L^a
[)ybPIv]
02EbmP
} -A\J:2a|
u\]aUP e
,XZ[L? >
/* BUozpqN}
**FileAccess.java YnCWmlC
*//文件访问(定位，写) DW,fh8w
package NetFox; z3lMD'uU3
import java.io.*; w,CZ*/^
CLU[')H0
ua'dm6",:
public class FileAccessI implements Serializable{ dE_I=v
DJF-J#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OcBn1k.
RandomAccessFile oSavedFile; >;ucwLi
long nPos; c20'{kH
?b&~(,A{
,uFdhA(i@'
public FileAccessI() throws IOException 2yFXX9!@
{ 4/rdr80
this("",0); n<x NE%
} &>!WhC16
tVf1]3(_>
LAoX'^6
public FileAccessI(String sName,long nPos) throws IOException gXR1nnK
{ %mda=%Yn
oSavedFile = new RandomAccessFile(sName,"rw"); x7s75
this.nPos = nPos; $jDp ^ -
oSavedFile.seek(nPos); ?2g\y@
} !7:~"kk
pFu3FUO*;
jx=2^A/i2-
public synchronized int write(byte[] b,int nStart,int nLen) ^H,oI*
{ 9J$z/j;X
int n = -1; fYU-pdWPT
try{ #\&jM -.-
oSavedFile.write(b,nStart,nLen); KL4Z||n
n = nLen; _a"\g9{%*
} CENA!WWQ
catch(IOException e) C7]K9
{ /}]Irj4m
e.printStackTrace (); } r#by%P
} F?LTWm
0 w"&9+kV
4YVxRZ1[3
return n; XG5mfKMt+
} XZaei\rUn)
C?FUc cI
8bB'[gJ]{
} J% B(4`
7[l "=
~D4%7U"dv
/* 0!n6tz lT
**SiteInfoBean.java T/V 5pYl
*/ XK)qDg
package NetFox; _Z:WgO].
hr8v O"tZN
r9/PmZo4x
public class SiteInfoBean { |WiK*
/&>6#3df-
3 *o l
private String sSiteURL; //Site's URL lW,rzJ1
private String sFilePath; //Saved File's Path Q<y&*o3YF|
private String sFileName; //Saved File's Name .1yp}&e#
private int nSplitter; //Count of Splited Downloading File =NH p%|
Og`6>?>97
> dJvl|
public SiteInfoBean() zkdyfl5
{//nSplitter的缺省值为5 3wEVjT-
//default value of nSplitter is 5 `N~;X~XFk
this("","","",5); Xi'y-cV ^
} p;dH[NW
Ly?gpOqu5
,X&lVv#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) JDi|]JY
{ lPh>8:qFM
sSiteURL= sURL; |0?h6
sFilePath = sPath; M@rknq@
sFileName = sName; .0:twj
this.nSplitter = nSpiltter; +$:bzo_u
sXm/+I^
R 2uo ZA,
} _2VL%
I3QK~ V*j)
\gRX:i#n
public String getSSiteURL() 9-Bp=M
{ GJ=<~S"
return sSiteURL; uI7 d?s
} >A#wvQl7
H gMLh*
;E/:_DWPD
public void setSSiteURL(String value) Ey$J.qw3
{ 'dYjbQ}~;
sSiteURL = value; AvdxDN
} Kd8V,teH
MP\$_;&xB
I"4j152P|
public String getSFilePath() " d3pkY
{ G\S\Qe{P~
return sFilePath; ngoo4}
} O1pBr=+j+{
u+eA>{
7a Fvj
public void setSFilePath(String value) zhbp"yju7
{ 9WsPBzi"T
sFilePath = value; XJ~_FiB
} `y; s1nL
H
~d :Z|8
public String getSFileName() E.]sX_X?
{ 7pDov@K<{
return sFileName; h V@C|*A
} <JE-#i
TIbqUR
jW5n^Y)
public void setSFileName(String value) "$KU+?
{ 8;YeEW5
sFileName = value; vr<6j/ty
} $}0q=Lg%wv
0S <;T+WA
/T`L;YE
public int getNSplitter() "Zd4e2>{M\
{ |Ui1Mm
return nSplitter; 4:-h\%
} !uLW-[F,
QLYb>8?"C
bE _=L=NG
public void setNSplitter(int nCount) iva&W
{ W8j)2nKD
nSplitter = nCount; L DD^X@q
} OI"vC1.5
} /gZrnd?
Qhb].V{utV
0UeDM*
/* $e#p -z
**Utility.java l\7NR
*/ '+1<7jl&I
package NetFox; s0"S;{_#
r+fR^hv
=D.M}xqo
public class Utility { t6&6kl
#W,BUN}
_sIhQ8$:
public Utility() B`)o?GcVN
{ *[jG^w0z8~
ALS\}_8
DytH} U"
} ~TCz1UWV
U2z1HIs
//线程睡眠 !0:uM)_k
public static void sleep(int nSecond) rmmN2+H
{ zRPXmu{t
try{ RWtD81(oC'
Thread.sleep(nSecond); Yz;Hu$/
} WbC|2!
catch(Exception e) 1a4HThDXP
{ ?ihkV?;)
e.printStackTrace (); 'L)@tkklp
} %E Jv!u*-
} j(mbUB*
`#B|l+baq
//日志 $},Y)"mI
public static void log(String sMsg) .C(Ir
{ ~TwjcI*/
System.err.println(sMsg); tjc3;9
} P]:r'^Yn
44 ,:@
mxsmW
public static void log(int sMsg) +c5z-X$^]
{ {aP5Mem
System.err.println(sMsg); DK 4 8
} l<qK' P4
} ~F?s\kp6
cmF&1o3_
o %sBU
/* q y73
**TestMethod.java 57IAH$n8o
*/ ^c3~CD5H 3
package NetFox; 6KPM4#61o
;$Q`JN=
'&,$"QXwE
public class TestMethod { eeb`Ao
rtf\{u9 }g
r4/G&m[V
public TestMethod() p x1y#Q
{ ///xx/weblogic60b2_win.exe IMLk{y%6
try{ 9lE[oAC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U<J4\|1?7'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^6s<
SiteFileFetch fileFetch = new SiteFileFetch(bean); )8vz4e Y
fileFetch.start(); @Z> {/
} ]TQ2PVN2
catch(Exception e){e.printStackTrace ();} v'uWmL7C
j:K>3?
$j*%}x~[
} %Cbqi.iuQ
|k$^RU<OF
FWI<_KZO
public static void main(String[] args) ]s-;*o\H
{ x? 3U3\W
new TestMethod(); W1S7%6y_1
} 8P5yaS_
} [sJ f)<
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