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)); i}e/!IVR3
} LGK&&srJs
for(int i=0;i<nEndPos.length-1;i++) 1N[9\Yi
{ 6e S~*
nEndPos = nStartPos[i+1]; LJ6L#es2
} Eunmc
nEndPos[nEndPos.length-1] = nFileLength; 388vdF
} AJ3%Z$JJ;s
} Jj/}GVNc7
y=0)vi{]
w^9< I]
//启动子线程 zR4]buHnE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; naM~>N
for(int i=0;i<nStartPos.length;i++) D\Y,2!I
{ n[B[hAT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R^mkQb>m.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zGdYk-H3TH
nStartPos,nEndPos,i); /'/i?9:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :p%#U$S4
fileSplitterFetch.start(); {+]tx46$
} W^7yh&@lU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UfIr"bU6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); - ~4na{6x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b!e0pFS;
nEndPos = " + nFileLength); LJ6l3)tpD
// fileSplitterFetch[nPos.length-1].start(); v>HOz\F
CH#K0hi
n.i8?:
//等待子线程结束 .SLpgYFL{
//int count = 0; ^f57qc3nF
//是否结束while循环 `v-O 4Pk
boolean breakWhile = false; MsZx 0]
artn _
peHjKK
while(!bStop) i&8|@CACb
{ &6vWz6!P
write_nPos(); +$Y*1{hyOo
Utility.sleep(500); r\cY R}v
breakWhile = true; 9Z }<H/q
9|3sNFGX
f[ 2PAz
for(int i=0;i<nStartPos.length;i++) )dFPfu&HL
{ 3yw$<lm
if(!fileSplitterFetch.bDownOver) oHr0;4Lg6
{ /M'd$k"0z
breakWhile = false; VR .t
break; XUKlgl!+.
} WNZYs
} V= -
if(breakWhile) )&O6d .
break; Mna yiJl
sgDSl@lB
rB{w4
//count++; &4+|{Zx0
//if(count>4) ]Y-Y.&b7t
// siteStop(); |N^"?bSt
} a]Pw:lT
h@Jg9AM
* nFzfV
System.err.println("文件下载结束！"); //;(KmU9
} "GR*d{
catch(Exception e){e.printStackTrace ();} qpMcVJL
} Te[v+jgLY,
W9pY=9]p+
nF_q{e7
//获得文件长度 AorY#oq
public long getFileSize() / Y od
{ 6VC|] |*
int nFileLength = -1; w@&z0ODJ
try{ I`*5z;Q!%@
URL url = new URL(siteInfoBean.getSSiteURL()); 7#d:TXS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gS'7:UH,
httpConnection.setRequestProperty("User-Agent","NetFox"); >~Xe` }'
'`|j{mBhG
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int responseCode=httpConnection.getResponseCode(); Vfga%K%l F
if(responseCode>=400) $,J0) ~
{ <ch}]-_
processErrorCode(responseCode); N$=9R
return -2; //-2 represent access is error (9oo8&GG
} j7MUA#6$
BWQ`8
SMIDW}U2S
String sHeader; cc*?4C/t
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LSA6*Q51
for(int i=1;;i++) p^*a>d:d]
{ H8I)D& cw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?O+.
//Utility.log(in.readLine()); &6C]|13;
sHeader=httpConnection.getHeaderFieldKey(i); ;l~a|KW0
if(sHeader!=null) {hJCn*m_
{ j~1K(=Ng
if(sHeader.equals("Content-Length")) !yPy@eP~
{ VBQAkl?(}4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u<uc"KY=
break; !L8q]]'XM
} qD4s?j-9
} ~?Vod|>
else n@ SUu7o
break; xGQP*nZ
} W4&8
} k}F7Jw#.
catch(IOException e){e.printStackTrace ();} `,xO~_ e>
catch(Exception e){e.printStackTrace ();} 'G~i;o 2
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Jz>P[LcB
Utility.log(nFileLength); Z^2SG_pD
= g &
xT_"` @
return nFileLength; LdH1sHy*d`
} 3o[(pfcU
K=HLMDs
.`m|Uf#" _
//保存下载信息（文件指针位置） 0RtZTCGO
private void write_nPos() )I3E
{ K<:%ofB"S
try{ c5$DHT@N"
output = new DataOutputStream(new FileOutputStream(tmpFile)); >n3GvZ5%
output.writeInt(nStartPos.length); y705
for(int i=0;i<nStartPos.length;i++) 2w3LK2`ZL
{ ']eN4H&=?}
// output.writeLong(nPos); &"JC8
output.writeLong(fileSplitterFetch.nStartPos); ^7/v[J<<
output.writeLong(fileSplitterFetch.nEndPos); 'g,_lF
} K=o {
output.close(); XJPIAN~l
} AV2Jl"1)z
catch(IOException e){e.printStackTrace ();} }dzVwP=
catch(Exception e){e.printStackTrace ();} p?>J86%[
} )K@D4sl
v5L+B`~
&! h~UZ
//读取保存的下载信息（文件指针位置） G gA:;f46
private void read_nPos() X!LiekU!D
{ fsPNxy"_
try{ EBW*v '
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L!l?tM o
int nCount = input.readInt(); gh*k\0
nStartPos = new long[nCount]; ]gVA6B?&9
nEndPos = new long[nCount]; t2{(ETV
for(int i=0;i<nStartPos.length;i++) -e(<Jd_=
{ MbCz*oW
nStartPos = input.readLong(); >*gf1"
nEndPos = input.readLong(); SF*mY=1
} r3U7`P
input.close(); d*Su c
} l![79eFp
catch(IOException e){e.printStackTrace ();} 5I6?gv/
catch(Exception e){e.printStackTrace ();} T88$sD.2 '
} 4qsct@K,
r9u'+$vmF
QxE%C
private void processErrorCode(int nErrorCode) ty~Sf-Pri
{ D*~Q;q>
System.err.println("Error Code : " + nErrorCode); Lf^ 7|
} Y=<ABtertS
jrN 5l1np
#e-7LmO~
//停止文件下载 5OGwOZAj52
public void siteStop() cJq{;~
{ 6x(b/`VW
bStop = true; lshSRir
for(int i=0;i<nStartPos.length;i++) ufR>*)_+
fileSplitterFetch.splitterStop(); Q+K]:c
85io%>&0
9-m_ e=jk6
} =v\}y+ Yh
} /_cpSq
//负责部分文件的抓取 3=ME$%f
**FileSplitterFetch.java rjcH[U(
*/ lY`WEu
package NetFox; "~=}&
@(a~p
M<Z#4Gg#4
import java.io.*; 8M!9gvcaO
import java.net.*; M^WoV }'
|n,O!29
4%nK0FAj
public class FileSplitterFetch extends Thread { g=4P-i3
hOLlZP+
l>`S<rGe
String sURL; //File URL : ciwh
long nStartPos; //File Snippet Start Position [*)2Ou
long nEndPos; //File Snippet End Position 4jZt0
int nThreadID; //Thread's ID K6B6@
boolean bDownOver = false; //Downing is over s!YX<V
boolean bStop = false; //Stop identical 7SkW!5
FileAccessI fileAccessI = null; //File Access interface mXJG &EA
gf9,/m
Dy. |bUB!f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mL}Wan
{ Iu~(SKr=|$
this.sURL = sURL; >/C,1}p[
this.nStartPos = nStart; /P3Pv"r|8]
this.nEndPos = nEnd; 6tVp%@
nThreadID = id; e jk?If 07
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8[^b8^
} E]a,2{&8<
t9W*N\
fF/;BSq'
public void run() ct*~\C6Ze
{ mrE>o!
while(nStartPos < nEndPos && !bStop) uKIR$n"
{ ri"=)]
x51p'bNy
w{;bvq%lY
try{ fH,h\0
URL url = new URL(sURL); p0Ij4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '#lEUlB
httpConnection.setRequestProperty("User-Agent","NetFox"); 'zt}\ Dt
String sProperty = "bytes="+nStartPos+"-"; o~:({
httpConnection.setRequestProperty("RANGE",sProperty); m7>)p]]
Utility.log(sProperty); 78ZbIL
V^G+_#@,,
UG}"OBg/
InputStream input = httpConnection.getInputStream(); =x^IBLHN
//logResponseHead(httpConnection); /WAOpf5
`a7b,d
:Z;kMrU
byte[] b = new byte[1024]; >]\oVG
int nRead; QE;,mC>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fok`-U
{ LwQYO'X
nStartPos += fileAccessI.write(b,0,nRead); ]tK<[8Y
//if(nThreadID == 1) = p2AK\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C0e oV}
} M|z4Dy
z*^vdi0
@DR?^ qp
Utility.log("Thread " + nThreadID + " is over!"); It'PWqZtG
bDownOver = true; d5LL( "
//nPos = fileAccessI.write (b,0,nRead); +{e2TY
} b Oh[(O!
catch(Exception e){e.printStackTrace ();} .ddf'$6h
} kf",/?s2Z
} '! ;Xxe5
5Obv/C
]'i}}/}u2
//打印回应的头信息 >Cr'dKZ}
public void logResponseHead(HttpURLConnection con) QN~9O^
{ #|l#
for(int i=1;;i++) )!`>Q|]}Zd
{ 3 _DJ
String header=con.getHeaderFieldKey(i); l(tMo7iPa
if(header!=null) DoJ3zYEk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5@Xy) z
Utility.log(header+" : "+con.getHeaderField(header)); VelX+|w
else 6CWm;%B#G
break; ?B4X&xf.D
} Fmrl*tr
} \%;5$ovV
v.H@Ey2
\"=@uqar2
public void splitterStop() .TRp74
{ \G]vTK3
bStop = true; {f%x8t$
} a*@4W3;7
tj!~7lo
_ <pO<S
} /kd6Yq(y
@z.HyQ_v
A,|lDsvM
/* N^tH&\G\m
**FileAccess.java -f[95Z3}
*//文件访问(定位，写) `>}e 5
package NetFox; Zo5.Yse
import java.io.*; lLeN`{?
`OyYo^+D|.
AqP7UL
public class FileAccessI implements Serializable{ uQg&A`4
F1zsGlObu}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e~BUAz
RandomAccessFile oSavedFile; ww{07g
long nPos; L{i|OK^e
Rlf#)4
:E9@9>3S
public FileAccessI() throws IOException 2SVJKX_V+
{ z2A1h!Me
this("",0); tJY3k$YX
} lMBXD?,,J
=arrp:
'd 6z^Z6
public FileAccessI(String sName,long nPos) throws IOException uzUZuJ
{ &!FWo@
oSavedFile = new RandomAccessFile(sName,"rw"); !+I!J s"
this.nPos = nPos; P"mD73a
oSavedFile.seek(nPos); gkDlh{
} Wd_KZ}lX
lAPvphO
4m$Xjj`vE
public synchronized int write(byte[] b,int nStart,int nLen) %g*AGu`
{ o]*#|4-
int n = -1; Tj*Vk $}0
try{ p8MPn>h<
oSavedFile.write(b,nStart,nLen); @5\ns-%
n = nLen; 6o/!H
} %CiZ>`5n#
catch(IOException e) UDz#?ZWnd
{ H-.8{8
e.printStackTrace (); VlQaT7Q
} n~NOqvT <
U#!f^@&AB
v=I 'rx
return n; (>\w8]
} ww"HV;i
CwVORf,uA
^8yhx-mgb
} wtw
564)ha/^(
YAf`Fnmw
/* x7]Yn'^'
**SiteInfoBean.java $R[ggH&
*/ /Z*XKIU6v/
package NetFox; Q7$K,7flf;
.-g++f(_i
KDX34Fr1
public class SiteInfoBean { \{ui{8+G
2,X~a;+
ESl</"<J
private String sSiteURL; //Site's URL #\]:lr{>?4
private String sFilePath; //Saved File's Path oopACE>
private String sFileName; //Saved File's Name HsGyNkr?r
private int nSplitter; //Count of Splited Downloading File IPhV|7
5h2@n0
*g<D p2`
public SiteInfoBean() *h>KeIB;
{//nSplitter的缺省值为5 AI&Bv
//default value of nSplitter is 5 T~rPpi&
this("","","",5); }t[?g)"M#-
} 5xawa:K
'bXm,Ed
_8CE|<Cn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m*MfGj(
{ *3A[C-1~.
sSiteURL= sURL; 1 f;k)x
sFilePath = sPath; E$'Zd,|f=
sFileName = sName; ,wN>,(
this.nSplitter = nSpiltter; ']hB_4v
(*Jcx:rH
H7KcPN(0
} =;9*gDfD
^Z{W1uYi
0]c 2T
public String getSSiteURL() wYrb P11
{ L/,W
return sSiteURL; <4{,u1!t
} ;:[!I]E0
2?9SM@nAY
_^<HlfOK
public void setSSiteURL(String value) y-TS?5Dr]
{ w34&m
sSiteURL = value; `H5n_km
} +|N!(H
h$Z_r($b
PyD'lsV
public String getSFilePath() vPn(~d_
{ e[HP]$\
return sFilePath; 8#9di
} ]F5qXF5
q#$4Kt;
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public void setSFilePath(String value) uj_ OWre
{ `43`*=
sFilePath = value; $W46!U3
} J2BW>T!tuw
}2^_Gaj
Cw<bu|?
public String getSFileName() .~+I"V{yF
{ 5h9`lS2
return sFileName; b{C3r3B8
} m/)Wn
I@l'Fx
ZE@!s3\
public void setSFileName(String value) 3d^zLL
{ jJc?/1jv
sFileName = value; Vj7(6'Hg
} f-N:
T [ `t?,
]bG8DEwD
public int getNSplitter() ^FJ=/#@T
{ ;&Q8xC2
return nSplitter; $d4^e&s
} 9Z,vpTE
!\Y85o>JU
OTA@4~{C
public void setNSplitter(int nCount) S{7*uK3$
{ N#-P}\Q9
nSplitter = nCount; E?o1&(2p
} t{\FV@R
} Ctpr.
?u/Uov@rD
7(;M
/* j$h.V#1z
**Utility.java [HJ^'/bB'
*/ PiMW29B^
package NetFox; PpPg ~ix*
opQ%!["N
=,q,W$-
public class Utility { b[<zT[.:
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<KF|QE
public Utility() (|_1ku3!
{ 'u }|~u?m
;iJ*.wVq
5CZii=@
} #<V/lPz+
CA7ZoMB#
//线程睡眠 hr&&"d {s
public static void sleep(int nSecond) m}\G.$h4
{ gVM9*3LH6
try{ 0oI3Fb;E
Thread.sleep(nSecond); 1ID0'j$
} TAbd[:2{F
catch(Exception e) isaDIl;L/
{ RF/I*5
e.printStackTrace (); .lVC>UT
} XK[cbVu
} zKr\S|yE
A;nrr1-0
//日志 L~_3BX
public static void log(String sMsg) l+BJh1^
{ \F;V69'
System.err.println(sMsg); ,bhOIuep3
} 8W$uw~|dw
tMxa:h;/x
L>~wcoB
public static void log(int sMsg) 3+mC96wN
{ OOy]:t4 /
System.err.println(sMsg); @= f2\hU
} ~^((tT
} m6J7)Wp
7%C6hEP/*W
" N)dle,
/* *oAv:8"iY
**TestMethod.java P;o6rQf
*/ +cQGX5 K
package NetFox; iHoQNog-!
h2g|D(u)
">vxYi
public class TestMethod { J%d\ 7
BdcTKC
QeP8Vl&e:
public TestMethod() Ws"eF0,'Z
{ ///xx/weblogic60b2_win.exe gBQK
try{ (uV~1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U4]>8L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8Fy$'Zx'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8&g|iG
fileFetch.start(); yyke"D
} T =r7FU
catch(Exception e){e.printStackTrace ();} M)td%<_
T|o[! @:,
!=j\pu} Z
} dI'cZt~n
0j*-ZvE)30
N*6Y5[g!\
public static void main(String[] args) bF:]MB^VK
{ (R)\
new TestMethod(); PZZTRgVc
} c,%9Fh?(
} VT1Nd
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