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)); U 1vZr{\
} 09/Mg
for(int i=0;i<nEndPos.length-1;i++) `Ps&N^[
{ 13kl\<6
nEndPos = nStartPos[i+1]; EjrK.|I0
} H>X:#xOA_
nEndPos[nEndPos.length-1] = nFileLength; ';Y0qitGB
} ]v=A}}kS
} 7*.nd
]De<'x}
''tCtG" Xi
//启动子线程 Fsz;T;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MaN6bM
for(int i=0;i<nStartPos.length;i++) ,N93H3(
{ u^, eHO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y'*oW+K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g%TOYZr!X
nStartPos,nEndPos,i); uVN2}3!)Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l|v`B6(
fileSplitterFetch.start(); >P@g].Q-
} !Ah v07SI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~bf4_5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XlLG/N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5If.[j{
nEndPos = " + nFileLength); *O_>3Hgl
// fileSplitterFetch[nPos.length-1].start(); F/V-@SF
6dgwsl~
`3g5n:"g\
//等待子线程结束 #zRHYZc'T|
//int count = 0; 9:R3+,ZN
//是否结束while循环 $7" Y/9Y
boolean breakWhile = false; C~Hhi-Xl)
r3qKT
^hNl6)hR
while(!bStop) >v2/0>U
{ SSxp!E'
write_nPos(); .do8\
Utility.sleep(500); |M`'
breakWhile = true; PriLV4?
bmu]zJ
zZ6m`]{B9?
for(int i=0;i<nStartPos.length;i++) 3^[P
{ eR%\_;}7;
if(!fileSplitterFetch.bDownOver) Om^(CAp
{ 9U8x&Z]P
breakWhile = false; 3\2%i6W6
break; @R%*;)*F
} vJxEF&X
} nNq<x^@83
if(breakWhile) <8(=Lv`)q
break; !B 4zU:d
d?&`ZVl
,Kl:4 Tv
//count++; nfbR"E jXr
//if(count>4) KCO.8=y3
// siteStop(); ynv{ rMl
} GF6o
TG[u3Y4
<pfl>Uf
System.err.println("文件下载结束！"); -w*fS,O
} f";pfu_FZ
catch(Exception e){e.printStackTrace ();} D%~tU70a
} hs[x\:})/
FY^2 Y
:`e#I/,
//获得文件长度 _aR{B-E
public long getFileSize() }[Z'Sg]s
{ j*@@H6G
int nFileLength = -1; Ym1vq=
try{ 4XNheP;b
URL url = new URL(siteInfoBean.getSSiteURL()); w%.hALN5-C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kN.;;HFq#
httpConnection.setRequestProperty("User-Agent","NetFox"); qmFG
5]>*0#C S
N]w_9p~=1
int responseCode=httpConnection.getResponseCode(); ?OLd }8y
if(responseCode>=400) ]R_R`X?
{ x>}ml\R
processErrorCode(responseCode); 7b+r LyS0
return -2; //-2 represent access is error r5DRF4,7
} tsAV46S
SK lvZ
Ww,\s5Uw
String sHeader; 3Rc*vVnI
S[1<Qrv]
;.V/ngaj
for(int i=1;;i++) l::q F 0
{ =SXdO)%2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2 ^m}5:0
//Utility.log(in.readLine()); j:h}ka/!p
sHeader=httpConnection.getHeaderFieldKey(i); Fp/{L
if(sHeader!=null) +P^ ;7"H
{ D`T;j[SsS#
if(sHeader.equals("Content-Length")) F{0\a;U@^
{ wAKHD*M)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jc&k-d>=G
break; '{"Rjv7
} ;cXw;$&D
} qD{1X25O
else ~Q&J\'GQH
break; KLyRb0V
} A`n>9|R
} --WQr]U/
catch(IOException e){e.printStackTrace ();} iApq!u,
catch(Exception e){e.printStackTrace ();} 4rU/2}.q
~w?02FU
w}ji]V}
Utility.log(nFileLength); ~[HzGm%
B&]`OO>O
k7^hcth
return nFileLength; BS9VwG<Z
} ZwkUd-=0i
n93q8U6m/U
zMsup4cl
//保存下载信息（文件指针位置） DZSS
private void write_nPos() pey=zR!
{ aKDY_D
try{ iFd !ED
output = new DataOutputStream(new FileOutputStream(tmpFile)); KqK]R6>
output.writeInt(nStartPos.length); *?FVLE
for(int i=0;i<nStartPos.length;i++) /65YHXg,
{ )9hqd
// output.writeLong(nPos); lq-KM8j
output.writeLong(fileSplitterFetch.nStartPos); Lc{AB!Br
output.writeLong(fileSplitterFetch.nEndPos); /eV)5`V
} Anz{u$0M[
output.close(); d4| )=
} Tn&_ >R
catch(IOException e){e.printStackTrace ();} y bhFDx
catch(Exception e){e.printStackTrace ();} !"N,w9MbD
} W'C>Fn}lO?
@IL04' \
|'h(S|
//读取保存的下载信息（文件指针位置） N3%#JdzZ$
private void read_nPos() _%e8GWf
{ bf_ >?F^
try{ ,Kv6!ib6Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3"h*L8No
int nCount = input.readInt(); 1#vu)a1+b
nStartPos = new long[nCount]; 0Y8gUpe3P6
nEndPos = new long[nCount]; mkSu $c
for(int i=0;i<nStartPos.length;i++) %g9ym@s
{ dla_uXtM6
nStartPos = input.readLong(); tx09B)0
nEndPos = input.readLong(); &W\e 5X<A
} zDvV%+RW)
input.close(); ,;pUBrz/[
} 7h\is
catch(IOException e){e.printStackTrace ();} p/{%%30ke
catch(Exception e){e.printStackTrace ();} I):c#
} G<CD4:V
`y>m >j
Ic'D#m
private void processErrorCode(int nErrorCode) YuhfPa
{ bW`nLiw}%
System.err.println("Error Code : " + nErrorCode); mnA_$W3~I
} EID-ROMO
_ s 3aaOL
QBa+xI_ J
//停止文件下载 PhAfEsD
public void siteStop() tR!C8:u
{ p*<Jg l
bStop = true; >#h,q|B
for(int i=0;i<nStartPos.length;i++) XJo.^<m
fileSplitterFetch.splitterStop(); H,D5)1Uu
;r@=[h
@fA{;@N
} 3HyOQD"{
} T={!/y+
//负责部分文件的抓取 !$NK7-
**FileSplitterFetch.java 8=D,`wog
*/ Y2VfJ}%Q
package NetFox; ?b7ttlX{
9,8/DW.K
Wrp~OF0k
import java.io.*; nReIi;pi
import java.net.*; -3ePCAtXbe
4rDVCXE
T'6`A<`3
public class FileSplitterFetch extends Thread { jTS8 qu
;8<HB1 &,
6D| F1UFU
String sURL; //File URL E,d<F{=8,o
long nStartPos; //File Snippet Start Position GG%;~4#2
long nEndPos; //File Snippet End Position 53hX%{3
int nThreadID; //Thread's ID w7`pbcY,
boolean bDownOver = false; //Downing is over dw;<Q
boolean bStop = false; //Stop identical t;+b*S6D
FileAccessI fileAccessI = null; //File Access interface [.&JQ
3*Q=)}
a(~X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nP[Z6h
{ v2tVq_\AMx
this.sURL = sURL; J#Q>dC7
this.nStartPos = nStart; E-1u_7
this.nEndPos = nEnd; H*G(`Zl}
nThreadID = id; }J?,?>Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .(/HUQn
} 'Ev[G6vo
}8AH/
dG+$!*6Z
public void run() \5tG>>c i
{ y_>DszRN`u
while(nStartPos < nEndPos && !bStop) BEax[=&W
{ R<fF ^^
&~;M16XM,e
!e<5JO;c
try{ e<uf)K=(C
URL url = new URL(sURL); ^>%.l'1/(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ` Ft-1eE
httpConnection.setRequestProperty("User-Agent","NetFox"); %7-(c
String sProperty = "bytes="+nStartPos+"-"; '0~?zP
httpConnection.setRequestProperty("RANGE",sProperty); E5A"sB
Utility.log(sProperty); _"x%s
@H$8;CRM
4<tbZP3/6)
InputStream input = httpConnection.getInputStream(); \^0>h`[
//logResponseHead(httpConnection); v.*fJ
0t7)x8c
F3vywN1$,
byte[] b = new byte[1024]; 6|'7Mr~\
int nRead; `3jwjy|5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _QHk&-Lp
{ ] 7[#K^
nStartPos += fileAccessI.write(b,0,nRead); Ohgu*5!o
//if(nThreadID == 1) SVZ@'X\[M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $,O8SW.O$
} O13]H"O_
ae-tAA[1Y
Lj|wFV
Utility.log("Thread " + nThreadID + " is over!"); zOA~<fhT
bDownOver = true; &HLG<ISw
//nPos = fileAccessI.write (b,0,nRead); [;aM8N
} F,)+9/S&
catch(Exception e){e.printStackTrace ();} QKEtV
} WI| -pzg
} &Jb$YKt
AvZ5?rN$
BUwL?
//打印回应的头信息 E@otV6Wk[@
public void logResponseHead(HttpURLConnection con) JFc,f
{ 2gklGDJD
for(int i=1;;i++) |15!D
{ XPf{R619
String header=con.getHeaderFieldKey(i); d3\?:}o,
if(header!=null) 'Q=)-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XXX y*/P
Utility.log(header+" : "+con.getHeaderField(header)); K"t?
else t90M]EAV
break; |*w)]2Bl
} j7:r8? G
} [*It' J^
2<OU)rVE4
3 eF c
public void splitterStop() @",#'eC"
{ ,<K+.7,)E
bStop = true; e<{d{
} {T^D&i# o
d])ctxB
{R63n
} ?[bE/Ya+S
B*}]'
U5-8It2OR
/* {Mb<onW
**FileAccess.java *p9)5
*//文件访问(定位，写) o~y{9Q
package NetFox; XRkUv>Yk
import java.io.*; )lt1I\n*k
;CS[Ja>e
*2~WP'~PQd
public class FileAccessI implements Serializable{ hR0a5
l,Y5VGiH#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mX.mX70|J
RandomAccessFile oSavedFile; W//+[
long nPos; x.t&NP^V)
=$bF[3D
>Ho=L)u
public FileAccessI() throws IOException 4?@#w>(
{ 'xai5X
this("",0); iNl<<0a
} 8;"%x|iBoL
t>%b[(a
v,Z]Vqk
public FileAccessI(String sName,long nPos) throws IOException D}}?{pe
{ \fC;b"j
oSavedFile = new RandomAccessFile(sName,"rw"); k0PwAt)65
this.nPos = nPos; 8Vn
oSavedFile.seek(nPos); KK>jV
} WdS1v%
A0A|cJP
]Z\W%'q+
public synchronized int write(byte[] b,int nStart,int nLen) '>1M~B
{ KLG.?`h:
int n = -1; Rl0"9D87z
try{ [ywF!#'){
oSavedFile.write(b,nStart,nLen); euT=]j
n = nLen; Cb<7?),vK
} 3l`"(5
catch(IOException e) 2<n18-|OQ
{ P%yL{
e.printStackTrace (); ljrJC
} nIBeZof
yr>J^Et%_
.i_ gE5
return n; KgD$P(J:[
} rDwd!Jet
B/lIn'=
"N&ix*($
} qR2cRepV
.^F&6'h1H
G] tT=X[
/* %j17QD8
**SiteInfoBean.java BIx*(
*/ d!&LpODI]*
package NetFox; +N,Fq/x
twldwuN
FO!0TyQ
public class SiteInfoBean { tQ'R(H`
Dvz 6 E
.uX(-8n ~
private String sSiteURL; //Site's URL 3ZSU^v
private String sFilePath; //Saved File's Path ';v2ld 9
private String sFileName; //Saved File's Name (qc<'$o
private int nSplitter; //Count of Splited Downloading File P*?2+.
JDnWBEV
u\xrC\Ka
public SiteInfoBean() 5gx;Bp^_
{//nSplitter的缺省值为5 Fgwe`[
//default value of nSplitter is 5 3~WI3ZIR
this("","","",5); Eqny'44
} +dq2}gM
>c:nr&yP
A~?)g!tS<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d@Bd*iI<
{ J$jLGy&'
sSiteURL= sURL; /-@F|,O)$n
sFilePath = sPath; 8BS Nm
sFileName = sName; (l2n%LL]*
this.nSplitter = nSpiltter; ~$ ?85
jgpF+V-n$
[["eK9}0
} XNvlx4
KV{
5?j#
public String getSSiteURL() y?}<SnjP:
{ mSFA i
return sSiteURL; "x_G6JE4tv
} VeFfkg4
KUq(&H7
pwVGe|h%,
public void setSSiteURL(String value) g6SZ4WV
{ NZ^hp\q
sSiteURL = value; YB{'L +Wbw
} 9I1`*0A
e5n"(s"G*[
ldaT: er9
public String getSFilePath() VF<VyWFC0`
{ VjiwW%UOM
return sFilePath; CA/Lv{[2
} XzBl }4s
KC<K*UHPAH
Fl==k
public void setSFilePath(String value) m{yq.H[X
{ e&<=+\ul
sFilePath = value; WZbRR.TxO
} '?mky,:HT
`7V'A
niPqzi
public String getSFileName() =AuxMEg
{ l>7?B2^<E
return sFileName; CT=5V@_u\
} W=K+kB
catJC3
jyRz53
public void setSFileName(String value) j'SGZnsy*
{ Ht~YSQ~:y
sFileName = value; ,YrPwdaTB
} 8/|1FI
J>0RN/38o
qi1#s,
public int getNSplitter() V67<Ky>
{ &:=[\Ws R
return nSplitter; <ZoMKUuB
} C^ ~[b o
xHn "D@
zgSv -h+f
public void setNSplitter(int nCount) Lyjp
{ `{nzw$
nSplitter = nCount; QLH6Nmk
} &WVRh=R
} JZ"XrS0?
chU,));F
8-Z|$F"
/* o5w =
**Utility.java 11-?M
*/ 4~0@(3
package NetFox; CN#2-[T
9P-I)ZqL
8wzQr2:
public class Utility { TI637yqCU
(0S;eM&
g;</|Z
public Utility() 9Qc=D"'
{ vb]H$@0
]Cc8[ZC
-Rr Qv(
} A!_yZ|)$T
q<Wz9lDMNR
//线程睡眠 )9V8&,
public static void sleep(int nSecond) j:J7
{ KA]5tVQA
try{ pm'i4!mY<P
Thread.sleep(nSecond); G/_9!lE
} NAEAvXj
catch(Exception e) )E=~ _`XO
{ TM`6:5ONv
e.printStackTrace (); o<i\1<eI
} "v5jYz5M
} Zl=IZ?F
N/eFwv.Er
//日志 q-d#bKIf
public static void log(String sMsg) 4[f>kY%[
{ !wEz= i
System.err.println(sMsg); -jL10~/
} iea7*]vW
=sh]H$
0^zp*u
public static void log(int sMsg) 5$"IUq*
{ pwr]lV$w
System.err.println(sMsg); \kVi&X=q:
} |j~{gfpSE
} {&s.*5
=&v&qne9
5TVA1
/* ?<eH!MHF
**TestMethod.java aj@<4A=;
*/ J={IGA
package NetFox; )w&k&TY4H
8YwSaBwO
2f7]=snCG
public class TestMethod { nM6/c
n~G-X
" )/febBS
public TestMethod() dI$M9;
{ ///xx/weblogic60b2_win.exe "o>gX'm*
try{ @DA.$zn&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {{ /-v3n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EiWsVic[
SiteFileFetch fileFetch = new SiteFileFetch(bean); CWS&f g%o{
fileFetch.start(); /yO|Q{C}M8
} 4]%v%64U
catch(Exception e){e.printStackTrace ();} #a=~a=c(^
*HXx;:
s2Hx?~
} "qvJ-Y
>'96SE3
\?rBtD(
public static void main(String[] args) !Xf7RT
{ iP^o]4[c
new TestMethod(); T9=55tpG9
} :ZP`Y%dt'
} >pq= .)X}
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