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)); s9fEx-!y
} GpR,n2
for(int i=0;i<nEndPos.length-1;i++) \\d8ulu
{ )5o6*(Y
nEndPos = nStartPos[i+1]; n-<`Z NMU
} T/J1 b-
nEndPos[nEndPos.length-1] = nFileLength; $%ww$3
} Vgy12dE
} 4=& d{.E
4]Gm4zO
~i>'3j0@k
//启动子线程 2<V`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %0f*OC
for(int i=0;i<nStartPos.length;i++) W4h]4X
{ (+u&b< <6N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &iy7It
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M[_Ptqjb
nStartPos,nEndPos,i); yC!>7@m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IQmlmu
fileSplitterFetch.start(); piIGSC
} hWbjA[a/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +hlR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?tT89m3_E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F0kQ/x
nEndPos = " + nFileLength); a"k,x-EL(
// fileSplitterFetch[nPos.length-1].start(); a@?ebCE
-YipPo"a
SF[Z]|0gs
//等待子线程结束 ^6!8)7b
//int count = 0; E <r;J
//是否结束while循环 |I.5]r-EK
boolean breakWhile = false; |(Xxi
W)Yo-%
i}))6
while(!bStop) V:AA{<
{ &kH7_Lz
write_nPos(); F5w=tK
Utility.sleep(500); 2D3mTpw
breakWhile = true; P1`YbLER5
wFBSux$
Imo?)dYK
for(int i=0;i<nStartPos.length;i++) p\]rxtm
{ obgO-d9l
if(!fileSplitterFetch.bDownOver) Jp~[Dm
{ L|A1bxt
breakWhile = false; \@_?mL@=
break; Jd33QL}Hj
} _IvqZ/6Y(
} Jb8%A@Z+
if(breakWhile) >R\!Qk
break; m`@~ZIa?>B
#Jfmt~ks'
+#@2,
//count++; t & 5s.
//if(count>4) H.[(`wi!I
// siteStop(); ZP.~Y;Ch;-
} U a1Z,~ *
}&EdA;/o_
^3Z~RK\}
System.err.println("文件下载结束！"); c>#3{}X|x%
} 1Msc:7:L
catch(Exception e){e.printStackTrace ();} O+~@S~
} {ka={7
m khp@^5
}y%mG&KSz
//获得文件长度 Acb %)Y
public long getFileSize() QEY#U|
{ 8oJp_sw
int nFileLength = -1; (i]0IYMXy*
try{ nTz( {q
URL url = new URL(siteInfoBean.getSSiteURL()); iDlg>UYd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pm|S>r
httpConnection.setRequestProperty("User-Agent","NetFox"); 0-Wv$o[
!LpFK0rw
V:1_k"zQ
int responseCode=httpConnection.getResponseCode(); 5>h# hcL
if(responseCode>=400) m=MM
{ ->@iw!5xu
processErrorCode(responseCode); ov'C0e+o
return -2; //-2 represent access is error #2qv"ntW
} @P<Mc)o^
M`|E)Y
q>VvXUyK,
String sHeader; 6W N(Tw
F2$?[1^f
%r:Uff@
for(int i=1;;i++) xx[l#+:c
{ EA<x$O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >]?!9@#IH
//Utility.log(in.readLine()); >jm^MS=
sHeader=httpConnection.getHeaderFieldKey(i); C.hRL4+;Zm
if(sHeader!=null) qmbhx9V
{ (.9H1aO46|
if(sHeader.equals("Content-Length")) |`@7G`x
{ >F;yfv;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ":01M},RA
break; 5Fa/Q>N
} WVh]<?GWXk
} V(6Ql j7
else #80r?,q
break; Qy|6A@
} ?xzDz
} 8"J6(KS
catch(IOException e){e.printStackTrace ();} =tqChw
catch(Exception e){e.printStackTrace ();} 0|`iop%(n
6i*LP(n
gqACIXR
Utility.log(nFileLength); XM?C7/^k
EdS7m,d
#e$vv!&}
return nFileLength; $R/@%U)-o
} 4d $T6b
n,%/cUl
4XArpKA
//保存下载信息（文件指针位置） `:EU~4s\
private void write_nPos() g42Z*+P6N
{ v^(J+d_>
try{ j79$/ Ol
output = new DataOutputStream(new FileOutputStream(tmpFile)); JS0957K
output.writeInt(nStartPos.length); QhmOO-Z?
for(int i=0;i<nStartPos.length;i++) to;cF6X
{ c$R<j'7
// output.writeLong(nPos); L ^{C4}x=
output.writeLong(fileSplitterFetch.nStartPos); -v?)E S
output.writeLong(fileSplitterFetch.nEndPos); 2B=+p83<
} MD=!a5'
output.close(); %1%@L7wP>
} w!m4
catch(IOException e){e.printStackTrace ();} \$D41_Wt|
catch(Exception e){e.printStackTrace ();} j'nrdr6n
} ? ]hS^&
km9@*@)
kaZ_ra;<
//读取保存的下载信息（文件指针位置） pDG>9P#mO
private void read_nPos() uZ(,7>0
{ A=pyaU`aE
try{ &3bhK5P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yjp*T:6
int nCount = input.readInt(); 'n!kqP
nStartPos = new long[nCount]; WEk3 4crk
nEndPos = new long[nCount]; td\'BV
for(int i=0;i<nStartPos.length;i++) mA0|W#NB
{ a3[lZPQe
nStartPos = input.readLong(); ]`_eaW?Ua
nEndPos = input.readLong(); o9AwW
} EMMp4KKOx+
input.close(); ?4MZT5 .
} r>x>aJ
catch(IOException e){e.printStackTrace ();} `NARJ9M
catch(Exception e){e.printStackTrace ();} t Ai?Bjo
} bKP@-<:]
$o>6Io|D
yU< "tgE
private void processErrorCode(int nErrorCode) s.jcD
{ n%={!WD
System.err.println("Error Code : " + nErrorCode); 1ppU ?#
} -{s9PZ3~_
_$BH.I
"BD$-]
//停止文件下载 95hdQ<W
public void siteStop() @8'LI8 \/
{ UWg+7RL
bStop = true; QKtVwsz +
for(int i=0;i<nStartPos.length;i++) :ej`]yK |
fileSplitterFetch.splitterStop(); pQ9~^
g%T`6dvT
2)47$eu
} 'w~e>$WI
} nj5Hls
//负责部分文件的抓取 1n )&%r
**FileSplitterFetch.java W`` -/
*/ \s">trXwX
package NetFox; P~7p~ke
Jqgo\r%`
Xe>
import java.io.*; i@hW" [A
import java.net.*; j`ybzG^
rz]M}!>k
A<<Bm M.%
public class FileSplitterFetch extends Thread { z2cd1HxN
^)0b= (.
YKG}4{T
String sURL; //File URL k#pNk7;MZ
long nStartPos; //File Snippet Start Position &)#bdt[
long nEndPos; //File Snippet End Position S7WT`2
int nThreadID; //Thread's ID O t1:z:Pl
boolean bDownOver = false; //Downing is over (=/}i'
boolean bStop = false; //Stop identical &VfMv'%x
FileAccessI fileAccessI = null; //File Access interface MgUjB~)Y
=%oQIx
&1$|KbmV4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UZb!tO2
{ ;;lOu~-*$p
this.sURL = sURL; i :Sih"=
this.nStartPos = nStart; JWo).
this.nEndPos = nEnd; u$V8fus0
nThreadID = id; I2^Eo5'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G "`t$=0
} y?.l9
9 `z^'k&
yjj)+eJ(Q
public void run() J\c\Ar:
{ !;h`J:dN
while(nStartPos < nEndPos && !bStop) /w2jlu}yt
{ >^ijj`{d
qjI.Sr70
7o4B1YD
try{ uhO-0H
URL url = new URL(sURL); ]iE)8X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~5sH`w~vQ
httpConnection.setRequestProperty("User-Agent","NetFox"); U t'r^
String sProperty = "bytes="+nStartPos+"-"; &NB"[Mm:@
httpConnection.setRequestProperty("RANGE",sProperty); 5;_&C=[
Utility.log(sProperty); ^U[yk'!Y
D~LU3#n
~;P>}|6Y
InputStream input = httpConnection.getInputStream(); r"\g6<RP
//logResponseHead(httpConnection); *e}1KcJ
Gn}^BJN
PWbi`qF)r
byte[] b = new byte[1024]; )R@M~d-o
int nRead; [2Ot=t6]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >nOzz0,
{ 85 <%L:EC
nStartPos += fileAccessI.write(b,0,nRead); sTChbks
//if(nThreadID == 1) tX 3y{W10"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `(Ij@84
} H!vX#
]#t5e>o|
$mLiEsJ
Utility.log("Thread " + nThreadID + " is over!"); {H[3[
bDownOver = true; E!zAUEVQm[
//nPos = fileAccessI.write (b,0,nRead); F`U YgN
} $ Ov#^wfA
catch(Exception e){e.printStackTrace ();} vQhi2J'
} ^dCSk==
} ;/|3U7{c
5B,HJax
i8H!4l
//打印回应的头信息 EGIwqci:
public void logResponseHead(HttpURLConnection con) f+W8Gszi
{ 9_I#{?
for(int i=1;;i++) 5_~QS
{ }&:F,q*
String header=con.getHeaderFieldKey(i); CY i{WV(:
if(header!=null) }}MZgm~U)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @!:_r5R~N
Utility.log(header+" : "+con.getHeaderField(header)); k:k!4
else ?QfomTT
break; y_A?}'X
} 95X!{\
} ;1[Lwnm
**L3T3$)
?)V}_%fVv
public void splitterStop() J0a#QvX!
{ 'p:L"L}Q?
bStop = true; h&$,mbEoI
} jFThW N
<;.->73E
ps=+wg?]
} %zA$+eT
&6}] v:
.e8S^lSl
/* qtLXdSc
**FileAccess.java gdVajOAu
*//文件访问(定位，写) wM#BQe3t#
package NetFox; P2^((c
import java.io.*; 0nOp'Ky\k
a{%]X(';
Up|>)WFw"
public class FileAccessI implements Serializable{ Jb4A!g5C
;%tu;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6a\YD{D] _
RandomAccessFile oSavedFile; z`Cq,Sz/
long nPos; 6 SosVE>Z
t4E=
byUz
public FileAccessI() throws IOException ;\gsd'i
{ ' y9yx[P
this("",0); !j|93*
} ,J0BG0jB^u
9BM 8
SWGD(]}uz
public FileAccessI(String sName,long nPos) throws IOException =P.m5e<
{ t%f6P
oSavedFile = new RandomAccessFile(sName,"rw"); CN"hx-f
this.nPos = nPos; / NlT[@T
oSavedFile.seek(nPos); 4[]/
} 5V{zdS=
0u'qu2mV
/\_wDi+#
public synchronized int write(byte[] b,int nStart,int nLen) dq{wFI)
{ Aj;F$(su
int n = -1; D/&^Y'|T
try{ Wqu][Wa[Z
oSavedFile.write(b,nStart,nLen); 0H-~-z8Y
n = nLen; G#pRBA^
} Z$? Ql@M
catch(IOException e) a|x1aN0
{ 8C{mV^cn~
e.printStackTrace (); x1}7c9nK
} :OVre*j
]OZk+DU:
BWct0=
return n; 9p#Laei].
} 2y&m8_s-p
@KhDQ0v]5
{5=Iu\e
} ByrK|lVM0
ZgcJxWC<
UtF8T6PKdW
/* $`Z-,AJc
**SiteInfoBean.java DUk&`BSJ
*/ ^0/FZ)V8
package NetFox; V #0F2GV<,
GN4'LU
"Z&-:1tP{9
public class SiteInfoBean { @,<@y>m7
nl)!)t=n
+h}>UK\
private String sSiteURL; //Site's URL 8X@p?43
private String sFilePath; //Saved File's Path }hralef #N
private String sFileName; //Saved File's Name b3G4cO;t;
private int nSplitter; //Count of Splited Downloading File G/nSF:rp
ZxmMw
^T[8j/9o^
public SiteInfoBean() G6C#M-S
{//nSplitter的缺省值为5 p`jkyi
//default value of nSplitter is 5 Q2c|sK8
this("","","",5); (cX;a/BR
} R^PPgE6!$
&@O]'
HJVi:;o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .{` :
{ "lcNjyU\O
sSiteURL= sURL; B\U9F5
sFilePath = sPath; YRXXutm
sFileName = sName; Ak`7f$z
this.nSplitter = nSpiltter; '~HCYE:5
G x;U 3iV
Q ke8BRBn
} ~C1lbn b
&_-,Nxsf
=IQ+9Fl2
public String getSSiteURL() }Ut*Y*
{ d NQ?8P-&
return sSiteURL; eI8rnp(Ia
} uD=i-IHT
>h^CC*&'pw
Mu,}?%
public void setSSiteURL(String value) AJ_''%$I3:
{ {:U zW\5l)
sSiteURL = value; v~f_~v5J!
} gnjh=anVX1
J1@X6U!{
u@j]U|FpY
public String getSFilePath() kvWP[! j?)
{ @>Y.s6a
return sFilePath; \LYB% K}
} {}r#s>
OF[y$<jM
CH!>RRF
public void setSFilePath(String value) h<)YZ[;x
{ [$PW {d8|
sFilePath = value; ,$"*X-1
} ObK-<kGcB
[1+ o
F1m 1%
public String getSFileName() +m|S7yr'
{ J7Z`wjX1
return sFileName; yQAW\0`
} |;~kHc$W
*P\$<4l
ZDMv8BP7
public void setSFileName(String value) ['<Q402:.
{ K90wX1&
sFileName = value; L#t^:%
} YJBlF2uD
v[k;R
R,]J~TfPK
public int getNSplitter() ,\YlDcl':0
{ D<V[:~-o
return nSplitter; ]]sy+$@~
} <1t.f}}uX
vy:-a G
T\ixS-%^
public void setNSplitter(int nCount) pr\wI?:k
{ A_h|f5
nSplitter = nCount; NOC8h\s}(
} q mJ#cmN
} 9'$\GN{0
$#z ` R;
.|$:%"O&X
/* 8iv0&91Z
**Utility.java 5 )A(q\
*/ }s9eRmJs
package NetFox; 9i6z p'
D8OW|wVE
(]_smsok
public class Utility { /nPNHO>U
B//2R)HS
nj90`O.K
public Utility() I{/}pr>
{ UFE# J
)9pRT dT
Gy]ZYo(
} `G@(Z:]f,t
b0(bL_,
//线程睡眠 f9%M:cl
public static void sleep(int nSecond) QIK;kjr*A3
{ \!51I./Q/
try{ 8I>'xf
Thread.sleep(nSecond); o4.?m6d
} qsA`\%]H
catch(Exception e) xYLTz8g=
{ -XJXl}M.
e.printStackTrace (); iQT$#"m n
} {uCXF~v
} pu"m(9
_c z$w5`
//日志 cv=H6j]h|
public static void log(String sMsg) w/1Os!p
{ kB! iEoIBA
System.err.println(sMsg); %2I >0
} >h Rq
*3!#W|#=]N
.UGbo.e
public static void log(int sMsg) dzbFUDJ
{ JS!`eO/8
System.err.println(sMsg); _{C =d3
} )N'-Ap$g
} x:? EL)(
_SQQS67fu"
Y00hc8<
/* UhX)?'J
**TestMethod.java gebDNl\Y2
*/ F*4zC@;
package NetFox; nB9(y4
t_"]n*zk1
E4cPCQyeH
public class TestMethod { )JXlPU
xt zjFfq
-)%gMD~z1
public TestMethod() K/l*Saj
{ ///xx/weblogic60b2_win.exe -Q MO*PY
try{ =M."^X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q3'L\_1L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dr gCr:Gf
SiteFileFetch fileFetch = new SiteFileFetch(bean); CQns:.`$`
fileFetch.start(); h|{DIG3
} PLueH/gC.
catch(Exception e){e.printStackTrace ();} ,Zva^5
vo"?a~kY7
]j+J^g
} oIv\Xdc81
iOdk)
DEQ7u`6
public static void main(String[] args) {'UK>S
{ l_i&8*=Px
new TestMethod(); D16w!Mnz{K
} r E&}B5PN=
} v 8B4%1NE
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