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)); la'e[t7
} Z#-k.|}
for(int i=0;i<nEndPos.length-1;i++) `n 3FT=
{ \Okc5;kB2
nEndPos = nStartPos[i+1]; S dIGU[fm
} &/s~? Iq
nEndPos[nEndPos.length-1] = nFileLength; hPan
} 0iYP
} 1"}B]5!
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Bul.RCP'
//启动子线程 aXe{U}eow
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~|&="K4,:
for(int i=0;i<nStartPos.length;i++) LeY+p]n~
{ q*L ]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sNm,Fmuz:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oW^k7#<e}
nStartPos,nEndPos,i); ~xS@]3n=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jCzGus!rM
fileSplitterFetch.start(); pd d|n2q
} I>{!U$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R N@^j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bRNK.[|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @]f3|>I
nEndPos = " + nFileLength); u7HvdLql
// fileSplitterFetch[nPos.length-1].start(); %yiD~&
|/VL35b
Uz 0W <u3v
//等待子线程结束 tpXa*6
//int count = 0; NCa~#i:F8
//是否结束while循环 A2y6UzLYD
boolean breakWhile = false; 2B-.}OJ
m}98bw
rFo\+//
while(!bStop) }sv!=^}BY3
{ ^IBGYl5n
write_nPos(); & g:%*>7P
Utility.sleep(500); %y>+1hakkX
breakWhile = true; Va7c#P?
~LbS~_\C=
O#Z/+\U
for(int i=0;i<nStartPos.length;i++) gmY/STN
{ a:A n=NA
if(!fileSplitterFetch.bDownOver) +0J@y1
{ |xh&p(
breakWhile = false; Z==!C=SBv
break; .U9R>#
} M#xQW`-`
} )u;JwFstX
if(breakWhile) .d~\Ysve
break; )GVBE%!WEd
Sk\n;mL:
4qt+uNe!
//count++; IZ*}idlkn/
//if(count>4) 'w(y J
// siteStop(); ;K_}A4K
} JWWYVl VC
f])M04<
NPm;
System.err.println("文件下载结束！"); 9JPEj-3`g
} T"?Y5t`(
catch(Exception e){e.printStackTrace ();} jv =EheD
} !EOQhh
.s2$al
G}VDEC
//获得文件长度 +3;Ody"59
public long getFileSize() g:_hj_1Y M
{ ;1 |x
int nFileLength = -1; rfs(#
try{ GP+2/D
URL url = new URL(siteInfoBean.getSSiteURL()); TnNWO+kg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y7z(&M@
httpConnection.setRequestProperty("User-Agent","NetFox"); .k@^KY
5;mRGY
KY$k`f6?P
int responseCode=httpConnection.getResponseCode(); i5"5&r7r
if(responseCode>=400) BFWi(58q
{ WuM C^
processErrorCode(responseCode); r?p[3JJ;mG
return -2; //-2 represent access is error EyY],W1 Y
} _({@B`N}
$W&:(&
XE1$K_m
String sHeader; vT c7an6fy
H_w%'v&
l4vTU=
for(int i=1;;i++) ?^9BMQ+
{ R4{-Qv#8 q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E1 |<Pt
//Utility.log(in.readLine()); XWUP=D~
sHeader=httpConnection.getHeaderFieldKey(i); X*F_<0RC1
if(sHeader!=null) cJDd0(tD!
{ M-J<n>hl
if(sHeader.equals("Content-Length")) LL(|$}yW
{ ZyI$M3{J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F2;:vTA>
break; eY,O@'"8`
} |0sPka/u16
} #G#g|x*V
else R,t$"bOd
break; S2K#[mDG
} %2"J:0j
} |sIr?RL{C
catch(IOException e){e.printStackTrace ();} 8#X_#
catch(Exception e){e.printStackTrace ();} PLA#!$c7q
rp's
m\ S\3n
Utility.log(nFileLength); O9s?h3
icgJ;Q 5
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return nFileLength; ObG=>WPJa
} j6S"UwJjp
q0&$7GH4
G:IP? z]
//保存下载信息（文件指针位置） j1*f]va
private void write_nPos() BT,b-= ;J-
{ \X|sU:g
try{ h|bT)!|
output = new DataOutputStream(new FileOutputStream(tmpFile)); w0w1PE-V=
output.writeInt(nStartPos.length); h3!$r~T!a:
for(int i=0;i<nStartPos.length;i++) PFrfd_s{>\
{ ]$A(9Pn"
// output.writeLong(nPos); };,/0Fu
output.writeLong(fileSplitterFetch.nStartPos); v.&>Ih/L
output.writeLong(fileSplitterFetch.nEndPos); GZ3 ]N
} n~.*1. P
output.close(); v2)g 1sXd
} < zOi4v0
catch(IOException e){e.printStackTrace ();} &nj&:?w
catch(Exception e){e.printStackTrace ();} "m$3)7 $
} Lrd[Ov
/<Ld'J
i47j lyH
//读取保存的下载信息（文件指针位置） ,"\@fwy{
private void read_nPos() lv%9MW0 z
{ -!e7L>w
try{ s?rBE.g@}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZnW@YC#9
int nCount = input.readInt(); W*N$'%
nStartPos = new long[nCount]; IH9.F
nEndPos = new long[nCount]; By)u-)g9
for(int i=0;i<nStartPos.length;i++) y<:<$22O
{ z>m=h)9d~
nStartPos = input.readLong(); P7.'kX9
nEndPos = input.readLong(); ^oM|<";!?D
} 9'[ N1Un.=
input.close(); }ns-W3B'
} (R!hjw~
catch(IOException e){e.printStackTrace ();} ~" i0x
catch(Exception e){e.printStackTrace ();} 1}%B%*N
} T/1gI9X
rl08R
pkgjTXR2b
private void processErrorCode(int nErrorCode) BlA[T%
{ "IQ/LbOqm_
System.err.println("Error Code : " + nErrorCode); 4_/?:$KO
} #V,R >0"
MGJ.,tK1
k8AW6oO/i
//停止文件下载 Wb}c=hZv
public void siteStop() yQNV@T<o
{ &;&ho+qD
bStop = true; n>>Qn&ym
for(int i=0;i<nStartPos.length;i++) k,yZ[n|`
fileSplitterFetch.splitterStop(); ?9{~> 4@
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ml`8HXK0
} #OO>rm$
} 'o_:^'c
//负责部分文件的抓取 iB[~U3
**FileSplitterFetch.java 0Hxmm@X2
*/ jho**TQ P
package NetFox; QX4ai3v
42J{aJVH
;r[@v347
import java.io.*; HlvuW(,x=
import java.net.*; W2FD+ wt
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gKYfQ+
public class FileSplitterFetch extends Thread { "ZM4F?x
E_e6^Sk5B(
.mLK`c6
String sURL; //File URL 4%nE*H%
long nStartPos; //File Snippet Start Position q@t0NvNSu
long nEndPos; //File Snippet End Position Zwz&rIQpT
int nThreadID; //Thread's ID ",7Q
boolean bDownOver = false; //Downing is over *!s;"U
boolean bStop = false; //Stop identical #|&Sc_#4)
FileAccessI fileAccessI = null; //File Access interface 1i[FY?6`dh
nw>8GivO
#9-P%%kQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (0YZZ93
{ /='. 4v
this.sURL = sURL; d)4 m6
this.nStartPos = nStart; CHrFM@CM
this.nEndPos = nEnd; p2Zo
nThreadID = id; 1cS}J:0P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8>,jpAN}r
} S"wR%\NIp
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public void run() ho##Z*O
{ = C4
while(nStartPos < nEndPos && !bStop) EkgE_8
{ r\qj!
W`\R%>$H
EQ'V{PIfj
try{ ?7<JQh)"e
URL url = new URL(sURL); Zjbc3M5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a}%#*J)!
httpConnection.setRequestProperty("User-Agent","NetFox"); =|3fs7
String sProperty = "bytes="+nStartPos+"-"; *%{gYpn
httpConnection.setRequestProperty("RANGE",sProperty); <B9C*M"4%
Utility.log(sProperty); *s9C!wYMZ
kY*rb_2j
&|f@$ff
InputStream input = httpConnection.getInputStream(); H,Z;=N_
//logResponseHead(httpConnection); rE}%KsZ
.C8PitS
sCR67/
byte[] b = new byte[1024]; =c/wplv*
int nRead; uV!^,,~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q09[[
{ +L7n<U3
nStartPos += fileAccessI.write(b,0,nRead); ma"3qGy
//if(nThreadID == 1) ]IoUwgpI)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VeW>[08
} ek#O3Oz
S H!
anXc|
Utility.log("Thread " + nThreadID + " is over!"); 0g0i4IV
bDownOver = true; ;W>k@L
//nPos = fileAccessI.write (b,0,nRead); l c+g&f
} 9FB19
catch(Exception e){e.printStackTrace ();} =EHUR'
} zuUW|r
} !o:f$6EA~C
D#3\y*-y?
rg^'S1x|
//打印回应的头信息 XUz3*rfs
public void logResponseHead(HttpURLConnection con) :A/d to
{ 5H*\t 7
for(int i=1;;i++) TWA-.>c
{ Z'"tB/=W
String header=con.getHeaderFieldKey(i); ILGMMA_2
if(header!=null) a(l29>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _d5QbTe
Utility.log(header+" : "+con.getHeaderField(header)); "wNJ
else 9I}-[|`u
break; Wf|Q$MHos
} gIjh:_ Pz
} 7@D@ucL
`$ 6rz
tfj:@Z5&$C
public void splitterStop() Qk:Y2mL
{ 8fl`r~bqZ
bStop = true; wne,e's}
} LDPUD'
`aciXlqIF
Lm%:K]X
} Tf'hc]`vS
G3Z)Z)N
%J+E/
/* KrQ1GepJ
**FileAccess.java #1OOU
*//文件访问(定位，写) e)d`pQ6
package NetFox; <g$~1fa
import java.io.*; !2ZF(@C/
;U-jO &
<0Xf9a8>
public class FileAccessI implements Serializable{ ? m DI#~)
E|iQc8gr&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F(>Np2oi6
RandomAccessFile oSavedFile; .+$Q<L
long nPos; <3LbNFP
32&;`]C
M/b Sud?@%
public FileAccessI() throws IOException .(K)?r-g5
{ ~E17L]ete
this("",0); 3LOdjT J
} e"|efE
KVclhT<F
VK m&iidU
public FileAccessI(String sName,long nPos) throws IOException '=b/6@&
{ {*G9|#[/@
oSavedFile = new RandomAccessFile(sName,"rw"); ].-1v5
this.nPos = nPos; h`^jyoF"(
oSavedFile.seek(nPos); dYJ(!V&
} y [}.yyye
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os=e|vkB*
public synchronized int write(byte[] b,int nStart,int nLen) u_oaebOrpP
{ k\5c|Wq|g
int n = -1; ~%&LTX0s|
try{ 9jM}~XvV
oSavedFile.write(b,nStart,nLen); H\ F:95
n = nLen; Lt64JH^lz
} <:+x+4ru
catch(IOException e) 5?{r
{ +^60T$
e.printStackTrace (); TM%|'^)
} ]cHgleHQ
)_YX DU
9X}10u:
return n; ]_f_w9]
} T(id^w
Q /U2^
$V-~Bu-
} gb[5&>(#
M?1Y,5
=^M/{51j
/* 6]K_m(F
**SiteInfoBean.java %O|iE M
*/ Ag-(5:
package NetFox; (KjoSN( K
+}Dw3;W}m
xQ7l~O b
public class SiteInfoBean { rBQ_iB_
<FV1Wz
G#ZH.24Y
private String sSiteURL; //Site's URL <sb~ ^B
private String sFilePath; //Saved File's Path }bb;~
private String sFileName; //Saved File's Name {'7B6
private int nSplitter; //Count of Splited Downloading File - YEZ]:"
G/)O@Ugp
6AAz
public SiteInfoBean() BX`{73sw
{//nSplitter的缺省值为5 D+rxT: d
//default value of nSplitter is 5 bQgc8/
this("","","",5); t%d Z-Ym
} 0yk]o5a++
rD*jp6Cl
cN/6SGHK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W=~~5jFX
{ ;AG8C#_
sSiteURL= sURL; .]8ZwAs=&
sFilePath = sPath; d[iQ`YW5
sFileName = sName; c[0}AGJ
this.nSplitter = nSpiltter; wON!MhA;
/CrSu
uy>q7C
} lU8l}Ndz"
}7b%HTF=
(~p< P+
public String getSSiteURL() ; 5*&xz
{ )3cAQ'w
return sSiteURL; j`{?OYD
} Y`~Ut:fZ
'g}!
<$D`Z-6
public void setSSiteURL(String value) sA+ }TNhq
{ /:cd\A}
sSiteURL = value; g@d*\ P)
} ]%;:7?5l
9)l$ aBa
#|uCgdi
public String getSFilePath() )HEa<P^kJl
{ [:7'?$
return sFilePath; #]\Uk,mhZB
} ^ gdaa>L
)*u8/U
`}p0VmD{NE
public void setSFilePath(String value) on4HKeO
{ iDpSj!x/_
sFilePath = value; mVj9,q0
} * `JYC
z0d.J1VW
/4yo`
public String getSFileName() sU=H&D99
{ D(~U6SR
return sFileName; D,k6$`
} f[]dfLS"W
H%[eV8
C"y(5U)d
public void setSFileName(String value) dn&s*
{ {y)=eX9
sFileName = value; CT&|QH{
} 5tl< 3g`
0j^Kgx
B`EJb71^Xy
public int getNSplitter() l5~os>
{ d9k0F OR1
return nSplitter; R|'ybW'Y
} AzPu)
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rjK%t|aV^
public void setNSplitter(int nCount) hqD*z6aH
{ @JGP,445
nSplitter = nCount; 49eD1h3'X[
} |44Ploz2b
} M$wC=b
R7%#U`Q^A
91/Q9xY
/* \UA[
**Utility.java L7l FtX+b
*/ ]>!K3kB
package NetFox; Z*F3G#A
11NQR[
9p]QM)M
public class Utility { HVRZ[Y<^
s9mx
p#-Z4-`
public Utility() rm7ANMB:
{ [z:!j$K
&0d#Y]D4`
9gW|}&-
} e+EQ]<M
8$=n j
//线程睡眠 ?d*z8w
public static void sleep(int nSecond) @@f"%2ZR[
{ GC-5X`Sq
try{ .e#w)K
Thread.sleep(nSecond); x[p|G5
} KR}?H#%
catch(Exception e) 9+|$$)
{ KM,\
e.printStackTrace (); }PlRx6r@
} jRa43ck
} ~g91Pr
#<fRE"v:Q
//日志 ZtNN<7
public static void log(String sMsg) (g]!J_Z"
{ 8\^R~K`sY
System.err.println(sMsg); Xg6Jh``
} 9X6h
Ov@gh kr
}CSDV9).S
public static void log(int sMsg) 1~gnc|?
{ l$KA)xbI
System.err.println(sMsg); t9lPb_70
} FaAC&F@u
} MpT8" /.]A
Q0sI(V#
hgG9m[?K
/* r `=I
**TestMethod.java '@v\{ l
*/ SO/c}vnBB
package NetFox; AYBns]!
[jQp~&nY
&u."A3(
public class TestMethod { CO/]wS
`v!urE/gg%
%@b0[ZC
public TestMethod() h,:m~0gmj
{ ///xx/weblogic60b2_win.exe ]h`&&Bqt
try{ LENq_@$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bIDj[-CDG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K-)] 1BG
SiteFileFetch fileFetch = new SiteFileFetch(bean); (XTG8W sN
fileFetch.start(); k=$TGqQY?
} ;nfdGB
catch(Exception e){e.printStackTrace ();} bW427B0
Wu/]MBM
BKCiIfkZ
} 5Pc;5 o0C
8Al{+gx@?
v4TQX<0s
public static void main(String[] args) -m zIT4
{ u{cW:
new TestMethod(); QT5TE: D
} a=_g*OK}D
} o'aEY<mZ7
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