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)); J.O;c5wL
} 7dU X(D,?
for(int i=0;i<nEndPos.length-1;i++) B`KpaE]
{ R$w=+%F
nEndPos = nStartPos[i+1]; "pHQ
} Is88+,O
nEndPos[nEndPos.length-1] = nFileLength; t$UFR7XE
} c?z%z&
} LU%g>?m.]
`D GO~RMp9
%*r Pd>*
//启动子线程 Vuz!~kLYIn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8K1+ttjm
for(int i=0;i<nStartPos.length;i++) ZY][LU~l8
{ Vxk0oIk`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1hRC Bwx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \3Xt\1qN4
nStartPos,nEndPos,i); eL-92]]e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !0zM@p
fileSplitterFetch.start(); Cf%)W:Q9
} B"{CWH O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x&8?/BR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KXdls(ROP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8(S'g+p
nEndPos = " + nFileLength); -pLb%f0?
// fileSplitterFetch[nPos.length-1].start(); 9K%E+_7b
P3N f<
sb8SG_c.
//等待子线程结束 !X#=Pt[,
//int count = 0; U>:p`@
//是否结束while循环 A}oR,$D-
boolean breakWhile = false; cvc.-7IO
'MC)%N,
j[=f;&1
while(!bStop) q 2=^l
{ jPbL3"0A&
write_nPos(); U8.DPRa
Utility.sleep(500); 5@Rf]'1B0
breakWhile = true; 0ED(e1K#B
wGbD%=
7AtJ6
for(int i=0;i<nStartPos.length;i++) ]bX.w/=
{ b},OCVT?
if(!fileSplitterFetch.bDownOver) &uk?1Z#j
{ W]reQ&<Z
breakWhile = false; eBBh/=Zc
break; 7] ~'8
} B%r)~?6DM
} LR`/pet
if(breakWhile) aP4r6lLv+
break; N(F9vZOs
WxIP~
P:CwC"z>sS
//count++; L18Olu
//if(count>4) #<l;YT8
// siteStop(); @n})oAC,
} d)q{s(<;
}.e*=/"MB
T\2cAW5
System.err.println("文件下载结束！"); bD49$N?>
} u6|7P<HUfb
catch(Exception e){e.printStackTrace ();} ,!Ah+x
} ?K}/b[[0v
f$/Daq <M
R#Ss_y
//获得文件长度 F5EKWP
public long getFileSize() b/2t@VlL
{ 6IeHZ)jGj
int nFileLength = -1; ~Uga=&
try{ 'm-s8]-W
URL url = new URL(siteInfoBean.getSSiteURL()); Vwl`A3Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bC"#.e
httpConnection.setRequestProperty("User-Agent","NetFox"); u QCQ$
O^`Y>>a
$L;7SY?
int responseCode=httpConnection.getResponseCode(); 5w{_WR6,
if(responseCode>=400) 9I.="b=J)
{ {OB\~$TH
processErrorCode(responseCode); [?]s((A~B
return -2; //-2 represent access is error wn|Sdp
} Q2iu}~
Rrk3EL
-S9$C*t
String sHeader; xNl_Q8Z?R^
D(L%fK`+
%hOe `2#$
for(int i=1;;i++) &{l?j>|TM
{ (}c}=V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _%"/I96'
//Utility.log(in.readLine()); -CxaOZG
sHeader=httpConnection.getHeaderFieldKey(i); )<jj O
if(sHeader!=null) n802!d+Tn
{ }JvyjE
if(sHeader.equals("Content-Length")) ?2DYz"/')
{ <BT}Tv9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #O`nQ
break; ~FDJKGK
} P>jlFm
} "TG}aS
else VxaJ[s3PQ&
break; kM@8RAxA
} 2sWM(SN
} 7pr@aA"vgj
catch(IOException e){e.printStackTrace ();} +dIg&}Tr
catch(Exception e){e.printStackTrace ();} lts{<AU~
3X%>xUI
9<,\+}^{
Utility.log(nFileLength); ;-U:t4
c1!h;(&
F&I^bkvh
return nFileLength; ={8ClUV#
} LXfDXXF
:'a |cjq
>L5[dkg%
//保存下载信息（文件指针位置） lHr?sMt
private void write_nPos() {n2jAR9nq
{ |)yO]pB:
try{ f~8Xue,l"
output = new DataOutputStream(new FileOutputStream(tmpFile)); >`\~=ivrD
output.writeInt(nStartPos.length); 62a{Ggs{
for(int i=0;i<nStartPos.length;i++) '}]w=2Lf
{ mI?AI7DqK
// output.writeLong(nPos); ZShRE"`
output.writeLong(fileSplitterFetch.nStartPos); t"JfqD E
output.writeLong(fileSplitterFetch.nEndPos); yj"+!g
} OG/R6k.
output.close(); `3\5&Bf
} K^?/
catch(IOException e){e.printStackTrace ();} W 4~a`D7
catch(Exception e){e.printStackTrace ();} ~b\bpu
} ,Q2`N{f
.kGg}
#!C/~"Y*`|
//读取保存的下载信息（文件指针位置） M|7xI
private void read_nPos() kf.w:X"i
{ -=QA{n
try{ ->$Do$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SUHyg/|F
int nCount = input.readInt(); 7s1FJm=Y/
nStartPos = new long[nCount]; )t&j0`Yq
nEndPos = new long[nCount]; $oe:km1-D
for(int i=0;i<nStartPos.length;i++) `epO/Uu\~u
{ ( *UMpdj
nStartPos = input.readLong(); >o%.`)Ar
nEndPos = input.readLong(); c$bb0J%
} 45q-x_
input.close(); b&s"x? 7
} Wyw/imr
catch(IOException e){e.printStackTrace ();} ~Wf&$p<|
catch(Exception e){e.printStackTrace ();} VuPa'2
} iO>2#p8$NR
+{4ziqYj
M7BJ$fA0E
private void processErrorCode(int nErrorCode) Nz\=M|@(#
{ <jY"+@rF
System.err.println("Error Code : " + nErrorCode); bK<'J=#1
} Mb"i}Yt{
gW$X8ECX
t1wNOoRa
//停止文件下载 S:+SZq
public void siteStop() }p]8'($
{ DO8@/W( `
bStop = true; I?EtU/AD
for(int i=0;i<nStartPos.length;i++) cxp>4[gH
fileSplitterFetch.splitterStop(); <`+U B<K
4&&((H
6"/cz~h
} hL+)XJu^J
} )Gh"(]-<
//负责部分文件的抓取 :l'61$=
**FileSplitterFetch.java ,n-M!y
*/ v#8{pr
package NetFox; N/4`afiV.
.|G([O^H
294 0M4
import java.io.*; QcU&G*
import java.net.*; dpxP
mr,IP=e~
Sbc
public class FileSplitterFetch extends Thread { ncuqo'r
s["8QCd"r
Oc}4`?oy<O
String sURL; //File URL h2QoBGL5
long nStartPos; //File Snippet Start Position [:&4Tp*C
long nEndPos; //File Snippet End Position x9hkE!{8
int nThreadID; //Thread's ID ocotO
boolean bDownOver = false; //Downing is over g+bc4eU
boolean bStop = false; //Stop identical ]p:s5Q
FileAccessI fileAccessI = null; //File Access interface mG*[5?=r
F\^9=}b_i
ifHQ2Ug9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2/<VoK0b
{ V\5ZRLawP
this.sURL = sURL; ( d#E16y
this.nStartPos = nStart; PJ5~,4H-4
this.nEndPos = nEnd; Z@4BTA
nThreadID = id; 'avzESe~'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ...|S]a
} w@ALl#z;}
^_0zO$z,
7_xQa$U[
public void run() :D|"hJ
{ +*Y/+.4WE$
while(nStartPos < nEndPos && !bStop) F=?0:2P0bD
{ IH(]RHTp%
4^/MDM@
F%Oy4*4
try{ yr8 b?m.x
URL url = new URL(sURL); &66-0d+Sh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G6]W'Kk
httpConnection.setRequestProperty("User-Agent","NetFox"); pN|BtrN{
String sProperty = "bytes="+nStartPos+"-"; =4+Wx8ZeW
httpConnection.setRequestProperty("RANGE",sProperty); 7jPPN
Utility.log(sProperty); #;4<dDVy
D"UCe7
l6]:Zcd0
InputStream input = httpConnection.getInputStream(); l.[S.@\=.
//logResponseHead(httpConnection); Gi]R8?M
W@Et
*DfwTbg|
byte[] b = new byte[1024]; E}LYO:
int nRead; 4HG;v|Cp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YflM*F`
{ #X1iig+
nStartPos += fileAccessI.write(b,0,nRead); eb&#sZ
//if(nThreadID == 1) olda't
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,/*L|M/&5
} =]i[gs)B
^Y[.-MJt+
qtlXDgppO
Utility.log("Thread " + nThreadID + " is over!"); !6.}{6b
bDownOver = true; }rK9M$2]u
//nPos = fileAccessI.write (b,0,nRead); ;7=pNK
} Y<0}z>^
catch(Exception e){e.printStackTrace ();} nsW#
} xDJ@MW#
} 1fajTT?
%{"v^4
>8%<ML
//打印回应的头信息 CCx_|>
public void logResponseHead(HttpURLConnection con) '9@} =pE
{ Fq>tl 64A
for(int i=1;;i++) $o}Ao@WkO
{ <Cv6wC=
String header=con.getHeaderFieldKey(i); .Y`;{)
if(header!=null) R2K{vs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B'[FnJ8~
Utility.log(header+" : "+con.getHeaderField(header)); 5AFy6Ab
else 1j4tR#L
break; ^phgNzD
} qrdA4S
} my|]:(_0d
DD$YMM
F{,<6/ayRz
public void splitterStop() E^'f'\m
{ y(81| c#
bStop = true; b~oQhU??"
} ZDn5d%
^/c v8M=
0o-.m
} u_31Db<
oJ4OVfknD
+hiskV@v
/* ^W8kt
**FileAccess.java }(MI}o}
*//文件访问(定位，写) qK=uSLo\+
package NetFox; nev@ykP6
import java.io.*; {"e)Jj_=
V7~tIhuJH
z.d1>w
public class FileAccessI implements Serializable{ `_;sT8
WZh%iuI{C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D_s0)|j$cy
RandomAccessFile oSavedFile; L[s7q0 F`l
long nPos; z:gp\
r~2>_LK
'aV/\a:*
public FileAccessI() throws IOException NQ&\t[R[
{ r.z=
this("",0); GycW3tc]_&
} c2E*A+V#u
SLsw '<
9I1D'7wI^^
public FileAccessI(String sName,long nPos) throws IOException Q{K'#
{ O%m\ Q1
oSavedFile = new RandomAccessFile(sName,"rw"); "39\@Ow
this.nPos = nPos; Xg4iH5!E
oSavedFile.seek(nPos); MJ.K,e
} nXRT%[o&
\5 S^~(iL
c;6[lv
public synchronized int write(byte[] b,int nStart,int nLen) Nv[MU@Tv
{ L|hoA9/]
int n = -1; E&z`BPd
try{ `xXpP"*o}
oSavedFile.write(b,nStart,nLen); ahoXQ8c:\}
n = nLen; y]U]b G{
} 4-r5C5o,W
catch(IOException e) _/c1b>kcso
{ NNgpDL*
e.printStackTrace (); '((pW
} '73g~T%$^*
>))f;$D=
rGDx9KR4K!
return n; ;n\$'"K&;
} d YliC
m8ApiGG
2j=i\B
} {9 .sW/
~NV 8avZ
`m")v0n3
/* d8C44q+ds
**SiteInfoBean.java `qs[a}%'>"
*/ eJ ;a}{ 4%
package NetFox; b0|;v-v
ASU.VY
ou\M}C`E
public class SiteInfoBean { ud grZ/w]
\?_M_5Nb
o)2KQ$b>Q
private String sSiteURL; //Site's URL C{<H)?]*BF
private String sFilePath; //Saved File's Path zg>)Lq|VsT
private String sFileName; //Saved File's Name '>:c:Tewy
private int nSplitter; //Count of Splited Downloading File S.,5vI"s,
Cm"7f!(#
oniVC',
public SiteInfoBean() Jk=_8Xvr`
{//nSplitter的缺省值为5 PP-U.
//default value of nSplitter is 5 ^&Vj m
this("","","",5); A)%!9i)
} MBn ZO
GoUsB|-\
q@=3`yQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e0:[,aF`
{ %o
sSiteURL= sURL; <p5?yF
sFilePath = sPath; 4K(oOxc9.
sFileName = sName; +ktubJ@Qgj
this.nSplitter = nSpiltter; IzI2w6a
4Q17vCC*n
nh'TyUd!
} \=&F\EV
M/a40uK
6* 6 |R93
public String getSSiteURL() /6{P ?)]pE
{ aN?^vW<
return sSiteURL; ?RPVd8PUhN
} =1r!'<"h
,CxIA^
90Bn}@t=Q
public void setSSiteURL(String value) IgyoBfj\d
{ 5q,ZH6\ {
sSiteURL = value; s9rKXY',:l
} M.oH,Kd6
&WKAg:^k)
d=C&b]
public String getSFilePath() Q+7+||RW
{ *!r"+?0gN
return sFilePath; +mRc8G
} Wl0p-h
mJ>msI @
G0Y]-*1
public void setSFilePath(String value) f\vMdY
{ b*)F7{/Z
sFilePath = value; 3EV?=R
} >&YUV.mLY
%?X6TAtH
mW=9WV
public String getSFileName() eh;L])~C
{ {!&^VXZIT
return sFileName; !~Ptnr`;
} z'01V8e
Y !%2vOt
:|%1i>O
public void setSFileName(String value) 8J)Kn4jq
{ 6L<QKE=
sFileName = value; %Y-5L;MI
} e'A1%g)
#h}a
;_S DW
public int getNSplitter() M2Jb<y]
{ hem>@Bp'V
return nSplitter; n{I1ZlEeh
} ,L=lg,lH^
Yb\d(k$h
B|K^:LUk9
public void setNSplitter(int nCount) MxDqp;
{ ]@!3os,CNF
nSplitter = nCount; l:+$Ks
} v^dQ%+}7>
} jG`,k*eUrJ
Bn{i+8I
wx8Qz,Z
/* Q9Vj8JO"{
**Utility.java 4Opf[3]
*/ 4I8QM&7
package NetFox; wvmcD%
$It3}?>C'
FQ"ED:lks
public class Utility { = N^Ec[u(l
4rLc] >
#T=e p0
public Utility() .hRtQU
{ Dkg^B@5Xr
M%Zh{
A|(!\J0
} }5AA}=
[]G@l. ]W
//线程睡眠 Q7]bUPDO
public static void sleep(int nSecond) GuC 9h^[=M
{ M5:j)oW
try{ ~ycWcZi>
Thread.sleep(nSecond); f#McTC3C
} wb>"'%
catch(Exception e) qr(t_qR&
{ yqC158 P
e.printStackTrace (); AC*SmQ\>!
} PqMu2 e
} \M;cF"e-S
qpjiQ,\:b
//日志 \]0#jI/:
public static void log(String sMsg) OX7a72z
{ WmOu#5*;
System.err.println(sMsg); GX=U6n>
} J"-/ok(<@
7 lSR
&4wwp!J
public static void log(int sMsg) -"EPU]q
{ j\HZ5
System.err.println(sMsg); #^tnRfS"
} %]1te*_
} |]~],
|\xTcS|d
Aho-\9/x%
/* mV0u:ws
**TestMethod.java 7x]q>Y8T
*/ -jzoGzC3
package NetFox; u2OrH3E4E3
26p_fKY
y@SI)&D
public class TestMethod { ehLn+tg
< lUpvr
b2H-D!YO^
public TestMethod() 0p+36g
{ ///xx/weblogic60b2_win.exe kjDmwa+91T
try{ 'w=aLu5dY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oIniy{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p +nh]
SiteFileFetch fileFetch = new SiteFileFetch(bean); U02
fileFetch.start(); FOhq&\nkU
} qDcoccEf
catch(Exception e){e.printStackTrace ();} 3 }3C*w+
8|nc($}~
x`Wb9[u8
} &Ez+4.srkh
Q!r&vQ/g
`(/xj{"Fr}
public static void main(String[] args) IBUFXzl
{ h;@>E:4Tg
new TestMethod(); @yj~5Gf(j
} P$]K
} \;iOQqv0&
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