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)); sdrWOq
} )AI?x@
for(int i=0;i<nEndPos.length-1;i++) "TfI+QgLF
{ <KX&zi<L)
nEndPos = nStartPos[i+1]; i0\)%H:z
} ?IILt=)<
nEndPos[nEndPos.length-1] = nFileLength; iUTU*El>
} f~q4{
} L"^OdpOs
5Dd:r{{ Q
s"WBw'_<<
//启动子线程 $C uR}g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6x/s|RWL1
for(int i=0;i<nStartPos.length;i++) }-74f
{ 9mDnKW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Kq>#I'%W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0'`S,
nStartPos,nEndPos,i); 6lsEGe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `"c'z;
fileSplitterFetch.start(); `;$h'eI9
} ->h5T%sn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;g+]klR!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KzNm^^#/$A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", { D+Ym%n
nEndPos = " + nFileLength); w.z<60%},0
// fileSplitterFetch[nPos.length-1].start(); ~@D/A/|
A@2Bs5F
e\D| o?v
//等待子线程结束 U7h(-dV
//int count = 0; a~opE!|m
//是否结束while循环 P#MK
boolean breakWhile = false; &<Zdyf?[Ou
8eN7VT eb
\x(^]/@
while(!bStop) f}iU& 3S
{ dw9Tf^V
write_nPos(); +P)ys#=
Utility.sleep(500); {~'H
breakWhile = true; u h)o
CW p#^1F
H O*YBL
for(int i=0;i<nStartPos.length;i++) [9AM\n>g
{ 'mE^5K
if(!fileSplitterFetch.bDownOver) cDIBDC
{ s6n`?,vw
breakWhile = false; APq7 f8t
break; @^&7$#jq%
} mlB~V3M'G
} moZm0`WR
if(breakWhile) ~8{sA5y
break; KP{3iUqvO
_{)9b24(
s$ z2 c
//count++; N 9LgU)-Jt
//if(count>4) uokc:D
// siteStop(); /8c&Axuv
} S)7/0N79A
ix&'0IrX*
lP3h<j
System.err.println("文件下载结束！"); orqJ[!u)`
} y' [LNp V
catch(Exception e){e.printStackTrace ();} cU8xUpq
} <cj{Qk
Ryv_1gR!
0` 5e
//获得文件长度 I2[]A,f,
public long getFileSize() 'SV7$,mK@
{ "r$/
int nFileLength = -1; )];aIA$
try{ tJ'iX>9I
URL url = new URL(siteInfoBean.getSSiteURL()); snC/H G7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FnE6?~xa
httpConnection.setRequestProperty("User-Agent","NetFox"); G3a7`CD
wxdyF&U n
:kG)sw7
int responseCode=httpConnection.getResponseCode(); x-;`-Uo%
if(responseCode>=400) t)a;/scT
{ HdNnUDb$B
processErrorCode(responseCode); !0"nx{7.
return -2; //-2 represent access is error N'?u1P4G
} bK*~ol
H M:r0_
T1bd:mC}n
String sHeader; kO_5|6
Ll}yJ#3,
K 1W].(-@4
for(int i=1;;i++) KY.ZT2k
{ 76@qHTh}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H=~9CJ+tc
//Utility.log(in.readLine()); (MLhaux-
sHeader=httpConnection.getHeaderFieldKey(i); +@:L|uFU
if(sHeader!=null) ,;jGJr
{ m3 -9b"
if(sHeader.equals("Content-Length")) *9D!A
{ N`$!p9r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3WUH~l{UJ
break; ,:GN;sIXg
} *y]+dK&-
} K{=PQ XSU
else #/70!+J_UF
break; (kw5>c7
} 93o;n1rS
} |He=LQ}0
catch(IOException e){e.printStackTrace ();} "rNL `P7
catch(Exception e){e.printStackTrace ();} SSA W52xC
C5X(U:
|.U)ll(c
Utility.log(nFileLength); q.V-LXM
{y-^~Q"z
rRb+_]Lg
return nFileLength; ^?GmrHC)
} y7lWeBnC
[TTSA2
z&}-8JykH
//保存下载信息（文件指针位置） go'j/4Tp
private void write_nPos() DBgMC"_
{ ^jSsa
try{ g0R[xOS|
output = new DataOutputStream(new FileOutputStream(tmpFile)); `u_Qa
output.writeInt(nStartPos.length); i.y)mcB4
for(int i=0;i<nStartPos.length;i++) l=={pb
{ 3z8C
// output.writeLong(nPos); ELD!{bMT
output.writeLong(fileSplitterFetch.nStartPos); JAjku6
output.writeLong(fileSplitterFetch.nEndPos); \".^K5Pm
} E>uVofhml
output.close(); ,r^"#C0J}
} 57I}RMT"
catch(IOException e){e.printStackTrace ();} jNyoN1M
catch(Exception e){e.printStackTrace ();} #&8rcu;/
} [V}, tO|
iK;opA"
CIC[1,
//读取保存的下载信息（文件指针位置） Lx[ ,Z,kD
private void read_nPos() diT=x52
{ cgT
try{ (<c7<_-H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =|U@
int nCount = input.readInt(); WO*9+\[v
nStartPos = new long[nCount]; LKF/u` 0dP
nEndPos = new long[nCount]; e%O0hE
for(int i=0;i<nStartPos.length;i++) k$i'v:c|:i
{ 01@t~v3!Z
nStartPos = input.readLong(); md Gwh7/3
nEndPos = input.readLong(); 04@cLDX8uB
} RHY4P4B<v>
input.close(); -:Rp'SJ
} EL{vFP
catch(IOException e){e.printStackTrace ();} nt :N!suP3
catch(Exception e){e.printStackTrace ();} 8Ogv9
} F-gE<<
9S7A!AKE
h2q/mi5{
private void processErrorCode(int nErrorCode) qUJ aeQ
{ p( LZ)7/
System.err.println("Error Code : " + nErrorCode); E-2eOT
} Y]g?2N=E
aUopNmN
vqdX^m^PY
//停止文件下载 obH;g*
public void siteStop() CI7A# 6-
{ aaW]JmRb
bStop = true; j<yiNHC
for(int i=0;i<nStartPos.length;i++) j}JZ
fileSplitterFetch.splitterStop(); q6d~V]4:
_e<o7Y@_
T6BFX0$
} A#y@`}]!'
} n6Z|Q@F
//负责部分文件的抓取 `ldz`yu6++
**FileSplitterFetch.java Me3dpF
*/ mTDVlw0dh
package NetFox; &, a3@i
Fke//- R
7<\C?`q"
import java.io.*; C(?blv-vM0
import java.net.*; 5FeFN)
@'2m$a
t*S." q
public class FileSplitterFetch extends Thread { hGTV;eU
Xl-e !
:l\V'=%9'@
String sURL; //File URL J$ut_N):N
long nStartPos; //File Snippet Start Position Lxl_"kG
long nEndPos; //File Snippet End Position I:j3sy
int nThreadID; //Thread's ID ~mz%E
boolean bDownOver = false; //Downing is over =r. >N\
boolean bStop = false; //Stop identical /F/;G*n
FileAccessI fileAccessI = null; //File Access interface XP?rOOn
ssQ BSbx
%yS3&Ju
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3251Vq %
{ H*I4xT@
this.sURL = sURL; G;iEo4\?
this.nStartPos = nStart; |UUdz_i!:
this.nEndPos = nEnd; P5<vf
nThreadID = id; aoW6U{\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <yUstz,Xu^
} L@Nu/(pB=
N_C;&hJN$w
4_?7&G0(
public void run() 'fd1Pj9~$
{ ib6^x:HGU
while(nStartPos < nEndPos && !bStop) AONDx3[
{ 2'0K WYM
uKr1Z2
|AZW9
try{ mh/n.*E7
URL url = new URL(sURL); 4Ft1@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "y?\Dx
httpConnection.setRequestProperty("User-Agent","NetFox"); W&Y"K)`
String sProperty = "bytes="+nStartPos+"-"; VyLH"cCv
httpConnection.setRequestProperty("RANGE",sProperty); eDKxn8+(H
Utility.log(sProperty); [#^#+ |{\
E>jh"|f:{
a}yXC<}$
InputStream input = httpConnection.getInputStream(); g=@_Z"
//logResponseHead(httpConnection); >pL2*O^{9
q>!L6h5]t
lEjwgk {
byte[] b = new byte[1024]; /! ajsn
int nRead; F'RUel_%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =3xE:
{ QP@<)`1t9
nStartPos += fileAccessI.write(b,0,nRead); iI1n2>V3y
//if(nThreadID == 1) iPG0o %
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *~XA'Vw!
} Kb;dKQ
/7c~nBU
$rB3m~c|
Utility.log("Thread " + nThreadID + " is over!"); :*514N
bDownOver = true; ]jMKC8uz
//nPos = fileAccessI.write (b,0,nRead); dtStTT
} S^I,Iz+`S'
catch(Exception e){e.printStackTrace ();} Dr<='Ux[5
} k`KGB
} <!d"E@%v@
"8f?h%t
j V3)2C}
//打印回应的头信息 h!@,8y[B
public void logResponseHead(HttpURLConnection con) JtKp(k&
{ d50Vtm\
for(int i=1;;i++) XKOUQc4!R
{ vT^Sk;E
String header=con.getHeaderFieldKey(i); Sb2v_o
if(header!=null) +xv!$gJEj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z`Wt%tL(
Utility.log(header+" : "+con.getHeaderField(header)); :fcM:w&
else c,EBF\r8*
break; \/`?
} =JLh?Wx
} x+5k <Xi}
SUCUP<G
9Ru;`
public void splitterStop() uLeRZSC
{ 5v.DX`"
bStop = true; d;[u8t
} M5L{*>4|6
R{Z-m2La
kK>Xrj6
} |iYg >
zSTR^sgJ
qeL pXe0c
/* Ji'(`9F&a
**FileAccess.java F'PQqb{
*//文件访问(定位，写) Lz9#A.
package NetFox; 9;t]Hp_+K
import java.io.*; M6|I6M<
I_)*)d44_
fN%jJ-[d
public class FileAccessI implements Serializable{ >u+q1j.
ZM#=`k9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _mE^rT
RandomAccessFile oSavedFile; 9W7#u}Z
long nPos; j|fd-<ng
le)DgIT>=
8ip7^
public FileAccessI() throws IOException .Ce8L&cU
{ OWjJxORB
this("",0); . v)mZp
} 0BPMmk
IakKi4(
`g''rfk}
public FileAccessI(String sName,long nPos) throws IOException 9<Eg}Ic
{ t G.(flW,
oSavedFile = new RandomAccessFile(sName,"rw"); $P o}
this.nPos = nPos; 'm=*u SJK
oSavedFile.seek(nPos); H!IshZfktn
} 5ABhj*7
[dX`K`k
z2c5m
public synchronized int write(byte[] b,int nStart,int nLen) M(q'%XL^
{ 4EP<tV
int n = -1; DC+wD Bp;
try{ SS|z*h Z
oSavedFile.write(b,nStart,nLen); 8y';\(;
n = nLen; v`[Eb27W.
} N^0uit
catch(IOException e) i8X`HbmN
{ ;Q0bT`/X
e.printStackTrace (); =1;=
} @ez Tbc3
K ?$#ntp
!<@J6??a}s
return n; ^nK7i[yF.k
} gYop--\14]
]uL+&(cr
Y$8JM
} t%1^Li
O;Y:uHf
=nUW'
/* [`=LTBt
**SiteInfoBean.java &<'n^n
*/ a?5[k}\
package NetFox; i7[uLdQ
`BFIC7a
~:Uwg+]j
public class SiteInfoBean { hPhZUL%
2 +5e0/_V
ZUXr!v/R:1
private String sSiteURL; //Site's URL #%3rTU
private String sFilePath; //Saved File's Path W1aa:hEf
private String sFileName; //Saved File's Name "O>n@Q|
private int nSplitter; //Count of Splited Downloading File 1r)kR@!LNG
YA(@5CZ
+A_J1iJ<
public SiteInfoBean() )x,8D ~p'
{//nSplitter的缺省值为5 O{z}8&oR:
//default value of nSplitter is 5 n";02?@F
this("","","",5); ,"}Rg1\4t
} 36m5bYMd)
yI{5m^s{
_A_ A$N~9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p\vMc\
{ 2 -!L _W(
sSiteURL= sURL; a@d=>CT$
sFilePath = sPath; 9~IQw#<
sFileName = sName; 0"k|H&
this.nSplitter = nSpiltter; [p r"ZQ]
Y]`.InG@
6qvp*35Cx
} E9!N>0
N@o?b
xh@-g|+g
public String getSSiteURL() eBN)g^
{ _#$9 y1bd
return sSiteURL; bucR">_p
} 7Ob*Yv=[
u8zbYd3
}}{!u0N},V
public void setSSiteURL(String value) 6"j_iB
{ {.e=qQ%P5)
sSiteURL = value; :q##fG'm/
} woH)0v
=/Aj
%T`U^Pnr
public String getSFilePath() =wu*D5
{ l?E a#
return sFilePath; SJ' % ^
} 7[v%GoE
+m\|e{G
{2'm^0Kl
public void setSFilePath(String value) Jhkvd<L8`m
{ 1MkI0OZE
sFilePath = value; XhU@W}}
} T".]m7!
9$K;Raz%
?0*8RK
public String getSFileName() 9|'B9C
{ }71LLzG`/
return sFileName; /Poet%XvRx
} (3vHY`9
`RQ#.
1,y&d}GW
public void setSFileName(String value) y9Y1PH7G
{ g{s'GyV8t
sFileName = value; FXKF\1`(H
} "HMP$)d
nCg66-3A
EEy$w1ec
public int getNSplitter() d4[(8} x$/
{ Tq<2`*Qs
return nSplitter; [}mA`5
} @* 1U{`
rWtZj}A
=#5D(0Ab
public void setNSplitter(int nCount) <T?oKOD ]
{ OqhD7 +
nSplitter = nCount; 6V9doP]i
} z(RL<N%
} ~K_Uq*dCE
<{(/E0~V/<
^o?SM^
/* > Vb@[
**Utility.java dHnR_.
*/ 6"T['6:j
package NetFox; k ^'f[|}
?q2j3e[>
UO`;&e-DB
public class Utility { AtS;IRN@
e`tLR- &
lkIn%=Z
public Utility() UK#&lim
{ yKagT$-
=?0lA_ 0
}`VDD?M
} <c[U#KrvJ
wHjLd$ +o
//线程睡眠 FwKj+f"
public static void sleep(int nSecond) vZ7gS
{ FaTa(3$%
try{ tU wRE|_
Thread.sleep(nSecond); G>qZxy`c
} ".*x!l0y7
catch(Exception e) co4h*?q
{ n#Dv2 E=6
e.printStackTrace (); gB,G.QM*6
} :S@1
} #(Or|\t
Id'RL2Kq*&
//日志 8cx=#Me
public static void log(String sMsg) <hnCUg1
{ l2%bF8]z
System.err.println(sMsg); ]-o"}"3Ef
} eg+!*>GaX
1B>Vt*=
I&9S;I$
public static void log(int sMsg) _&3<6$}i"
{ |iFVh$N
System.err.println(sMsg); <3PL@orO
} u),Qa=Wp
} TjK{9A
{npcPp9
_#e&t"@GS
/* v ]Sl<%ry
**TestMethod.java gJt`?8t
*/ Bc-yxjsw
package NetFox; SZ![%)83
S/vf'gj
rtJl _0`
public class TestMethod { tqPx$s
q}uHFp/J
W_O)~u8
public TestMethod() a\uie$"cr]
{ ///xx/weblogic60b2_win.exe /T^ JS
try{ 5M]z5}n/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hk_y/97OO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v}G]X Z8
SiteFileFetch fileFetch = new SiteFileFetch(bean); z7.|fE)<6
fileFetch.start(); _?7#MWe&
} C9n}6Er=,
catch(Exception e){e.printStackTrace ();} >C WKH~
5(2|tJw-H;
"bg'@:4F
} g3@Rl2yQJ
;Lw{XqT
M_0zC1
public static void main(String[] args) 1xNVdI
{ HJ?+A-n/
new TestMethod(); $h9='0Wi0'
} Uv_N x10
} ~cAZB9Fa
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