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)); [5uRS}!
} A |3tI
for(int i=0;i<nEndPos.length-1;i++) 7zHh@ B:]
{ jCrpL~tWT
nEndPos = nStartPos[i+1]; H|ER
} srYJp^sC
nEndPos[nEndPos.length-1] = nFileLength; 7ULqo>j
} nPs7c %
} oyNSh8c7c
zGc: @z
n+BJxu?
//启动子线程 3/b;7\M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +,yK;^b
for(int i=0;i<nStartPos.length;i++) zoDH` h_
{ yuDZ~0]R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TYlbU<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {X*^s5{;H
nStartPos,nEndPos,i); ;b`[&g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K =wBpLB
fileSplitterFetch.start(); XuD=E
} rHf&:~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +J{0 E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <JV"@H=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Kh4$ wwn
nEndPos = " + nFileLength); +<}0|Xl&
// fileSplitterFetch[nPos.length-1].start(); NM0tp )h
ZxlAk+<]
aB]m*~
//等待子线程结束 <)\y#N
//int count = 0; 7lS#f1E
//是否结束while循环 p/2jh&
boolean breakWhile = false; {@<J_A
&f7fK|}
V\})3i8
while(!bStop) 0]D{Va
{ bJYda)
write_nPos(); 6m VuyI
Utility.sleep(500); t^[8RhD
breakWhile = true; xB@|LtdO9;
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h.!}3\Y
for(int i=0;i<nStartPos.length;i++) =56T{N
{ pSm $FBW h
if(!fileSplitterFetch.bDownOver) % ,N<
{ 0<8XI>.3D
breakWhile = false; UjOB98Du
break; }?&k a$rI
} Y!WG)u5
} ,R$u?c0>'&
if(breakWhile) <H0R&l\
break; `'\t$nU
4;HJ;0-ps
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//count++; n!')wIk
//if(count>4) 5C"QE8R o
// siteStop(); <5G{"U+ \
} .`7cBsXH
N`E-+9L)
8/t$d#xHI
System.err.println("文件下载结束！"); h'$QC )P
} rJa$9B*^
catch(Exception e){e.printStackTrace ();} "+zCS|
} sP-^~ pp
@]qBF]6
XxDaz1
//获得文件长度 _:+ KMR
public long getFileSize() O:{U^K:*
{ DAwqo.m
int nFileLength = -1; gPu2G/Y
try{ sHcTd>xS
URL url = new URL(siteInfoBean.getSSiteURL()); ]`bQW?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MWNPPYww
httpConnection.setRequestProperty("User-Agent","NetFox"); 11|Rdd+}
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L{E^?iX
int responseCode=httpConnection.getResponseCode(); %L [&,a
if(responseCode>=400) pA;-vMpMj
{ e(NLX`
processErrorCode(responseCode); `]LSbS
return -2; //-2 represent access is error /XudV2P-CA
} 4CQ"8k(S"
wnTV|^Q
lNv".Y=l
String sHeader; $7QoMV8V
zE)~0v4
Fb/XC:AD
for(int i=1;;i++) QI]Ih
{ Sa"9^_.2#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'TTUN=y
//Utility.log(in.readLine()); PyA&ZkX>
sHeader=httpConnection.getHeaderFieldKey(i); ^1Xt]T`e
if(sHeader!=null) }n7th
{ bu&t'?zx!
if(sHeader.equals("Content-Length")) aF|d^
{ `z0{S!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XE3'`D!
break; ,Rx{yf]k
} ?0_7?yTR/
} .bVmqR`
else _SACqamo5s
break; JlKM+UE:
} +,v-=~5
} ubu?S%`
catch(IOException e){e.printStackTrace ();} &TG5rUUg
catch(Exception e){e.printStackTrace ();} 7O`o ovW$
W23]Bx
SEl#FWR
Utility.log(nFileLength); u*7Z~R
!GW,\y
aZKOY
return nFileLength; r-kMLw/)
} PY3ps2^K.
>/<:Q &
0F#>CmD
//保存下载信息（文件指针位置） 4f~["[*ea
private void write_nPos() F?m?UQS'u
{ zq1mmFIO
try{ hh~n#7w~IR
output = new DataOutputStream(new FileOutputStream(tmpFile)); 51#"3S
output.writeInt(nStartPos.length); &x-TW,#Ks
for(int i=0;i<nStartPos.length;i++) qn"D#K'&(
{ `o79g"kxe
// output.writeLong(nPos); !:LJzROh
output.writeLong(fileSplitterFetch.nStartPos); o{*ay$vA]
output.writeLong(fileSplitterFetch.nEndPos); CK_(b"
} *n(> ^
output.close(); _{jP;W
} sA9&/p/
catch(IOException e){e.printStackTrace ();} ^MD;"A<
catch(Exception e){e.printStackTrace ();} 8hA^`Y
} Fg/dS6=n`?
XYx6V
gPzL*6OSA
//读取保存的下载信息（文件指针位置） h{lDxOH*
private void read_nPos() 44\>gI<
{ 7@a 0$coP
try{ 8u2+tB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ni
int nCount = input.readInt(); }.)s%4p8
nStartPos = new long[nCount]; cgC\mM4Nla
nEndPos = new long[nCount]; z"DkFvA
for(int i=0;i<nStartPos.length;i++) A>NsKWf{
{ XE}H3/2
nStartPos = input.readLong(); }<MR`h1
nEndPos = input.readLong(); +:6Ii9GN
} Lt#'W
input.close(); 5j"1z1_&
} SbsouGD,{
catch(IOException e){e.printStackTrace ();} Ni*Wz*o
catch(Exception e){e.printStackTrace ();} .BO<
} RA a[t :|
Bn]K+h\E
7:h!Wj-a]
private void processErrorCode(int nErrorCode) <-UOISyf
{ J NC
System.err.println("Error Code : " + nErrorCode); n,P5o_^:
} Swtbl`,
:9l51oE7
\g-j9|0
//停止文件下载 p4VqV6LwD
public void siteStop() LF*Q!
{ |0bc$ZY:
bStop = true; 2aw&F Z?
for(int i=0;i<nStartPos.length;i++) BbJkdt7
fileSplitterFetch.splitterStop(); }tST)=M`
^T4Ay=~{
;52'}%5
} Jf:,y~mV
} km:nE: |
//负责部分文件的抓取 H L<s@kEZ
**FileSplitterFetch.java tn/T6C^)
*/ Z\>, ),O
package NetFox; cJn HW
0)uYizJce
}xn_6
import java.io.*; }bB`(B,m
import java.net.*; h3u1K>R)
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,:v&4x&=
public class FileSplitterFetch extends Thread { @?B6aD|jE
=G-N` 39
6k])KlJ2;
String sURL; //File URL 4ax|Vb)D
long nStartPos; //File Snippet Start Position W^g[L:s
long nEndPos; //File Snippet End Position w,.qCpT$_
int nThreadID; //Thread's ID ySdN;d:q
boolean bDownOver = false; //Downing is over N:+ taz-
boolean bStop = false; //Stop identical fW0$s`
FileAccessI fileAccessI = null; //File Access interface wpPn}[a
83]PA<R
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]]iO- }
{ qFRdg V>8
this.sURL = sURL; 96|[}:+$&:
this.nStartPos = nStart; y@vj;3:
this.nEndPos = nEnd; 2%rLoL$Y2+
nThreadID = id; &hZwZgV+3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B(HT.%r^A
} p5]_}I`+2
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{_ V0
public void run() "/x_>ui1F
{ LZ~`29qw(
while(nStartPos < nEndPos && !bStop) ~o15#Pfn/
{ T|'&K:[TJ
b#Kq[}
(wt+`_6
try{ =_=*OEgO]
URL url = new URL(sURL); *:_~Nn9_R;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /Ic[N&
httpConnection.setRequestProperty("User-Agent","NetFox"); OHp5z? z
String sProperty = "bytes="+nStartPos+"-"; p6 xPheD
httpConnection.setRequestProperty("RANGE",sProperty); v"1Po_`
Utility.log(sProperty); BD;H
zQuM !.
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InputStream input = httpConnection.getInputStream(); @Jv# fr
//logResponseHead(httpConnection); #V 43=
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byte[] b = new byte[1024]; jMpa?Jp1
int nRead; SN]LeXesS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,jh~;, w2
{ -l*A
nStartPos += fileAccessI.write(b,0,nRead); \aSz2lxEHn
//if(nThreadID == 1) ZCiY,;c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o42`z>~
} Pern*x9$
{7#03k
WfVMdwz=
Utility.log("Thread " + nThreadID + " is over!"); K;kM_%9u
bDownOver = true; C|e+0aW
//nPos = fileAccessI.write (b,0,nRead); `1'5j "v
} 9&jPp4qG
catch(Exception e){e.printStackTrace ();} LdWc X`K
} >BiRk%x
} IcoowZZ
70iH0j)
>!BFt$sd
//打印回应的头信息 TgaYt\"i[
public void logResponseHead(HttpURLConnection con) <f%/px%1
{ 9Q[>.):
for(int i=1;;i++) -0|K,k
{ W);W.:F
String header=con.getHeaderFieldKey(i); xh'^c^1
if(header!=null) #( uj$[o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <'*4j\*
Utility.log(header+" : "+con.getHeaderField(header)); qZ\L
else @ ^.*$E5
break; Ml`vx
} %8D?$v"#Z
} 1X@b?6
A@ VaaX
@l>Xnqx)
public void splitterStop() 6"%qv`.Fp
{ w~-X>~}
bStop = true; ( pD7
} vgk9b!Xd
Vipp /WV
~%P3Pp
} e[4V%h
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/* T&/_e
**FileAccess.java nLd~2qBuv
*//文件访问(定位，写) &z ksRX
package NetFox; 5P\N"Yjx'
import java.io.*; _;G=G5r
iwo$\
/co%:}ln
public class FileAccessI implements Serializable{ 3H'*?|Y(#
FfXZ|o$;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `vEqj v
RandomAccessFile oSavedFile; b`]M|C [5
long nPos; *<dHqK`?C
u+DX$#-n!]
j |td,82.
public FileAccessI() throws IOException 5B|,S1b
{ \3j)>u,r
this("",0); AfE%a-;:
} ZYKd
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n_;S2KM
public FileAccessI(String sName,long nPos) throws IOException 'z](xG<
{ DPeVKyjU
oSavedFile = new RandomAccessFile(sName,"rw"); {rfte'4;=
this.nPos = nPos; Y-~;E3(
oSavedFile.seek(nPos); ?Ccw4]YO,=
} bX&e_Pd
T/Q==Q{W:
2fP~;\AP
public synchronized int write(byte[] b,int nStart,int nLen) 9fCO7AE0#
{ <?4cWp|i
int n = -1; -pX|U~a[
try{ jJ-d/"(
oSavedFile.write(b,nStart,nLen); V0T<eH<
n = nLen; U#"WrWj
} g-eq&#
catch(IOException e) T0?uC/7H
{ nrbazyKm
e.printStackTrace (); fp-m.d:|
} I4ctxMVP
3.~h6r5-
9 P~d:'Ib
return n; xH@'H?
} tx)OJY
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X\'E4
} z.j4tc9F/5
j88=f#<
?q6Z's[
/* 8E 9{ Gf
**SiteInfoBean.java ?"u'#f_
*/ )O -cw7 >
package NetFox; 26}u4W$
FdM<;}6T
g~|y$T
public class SiteInfoBean { R9q0,yQW
;x16shH
!c."
private String sSiteURL; //Site's URL <L2GUX36#
private String sFilePath; //Saved File's Path -O /T?H
private String sFileName; //Saved File's Name *bU% @O
private int nSplitter; //Count of Splited Downloading File uYabJqV
]'6'<S
<B=[hk!
public SiteInfoBean() {9Xm<}%u]]
{//nSplitter的缺省值为5 gu!](yEgl
//default value of nSplitter is 5 [JZ h*A
this("","","",5); Eh {up
} *F|i&2
/Go>5B>
{sl~2#,}b1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) avVmY|I
{ wn{]#n=|l
sSiteURL= sURL; InP[yFV-z
sFilePath = sPath; ~@?"'!U
sFileName = sName; ,,Jjr[A_j
this.nSplitter = nSpiltter; /[6:LnaE
[~!.a\[RW
,5=kDw2
} e7lo!(>#
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cNx \&vpd
public String getSSiteURL() i<J^:7
{ i'Wcf1I-=
return sSiteURL; 89db5Dx
} LH,]vuXh
E`(5UF*>
VZt;P%1;h
public void setSSiteURL(String value) \u{Jf'g
{ R !Fx)xj
sSiteURL = value; Kyu@>9Ok
} An/>05|
k"5`:qL
\ hrBq^I
public String getSFilePath() 4bPqmEE
{ G 2!}R
return sFilePath; ypgliq(
} IN<:P
>G<4Ro"
+jv}\Jt
public void setSFilePath(String value) G2=F8kL
{ D8gQRQ
sFilePath = value; ?U}sQ;c$
} vwm|I7/w
y9=t;qH@|
)nJzSN=>$
public String getSFileName() 1bT'u5&
{ ]"C| qR*
return sFileName; YGfA qI y
} gHp'3SnS
>c}:
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public void setSFileName(String value) ^8b~ZX
{ ! Zno[R
sFileName = value; QjehDwt|
} c5Z;%v |y
?OdV1xB
UB5}i('L
public int getNSplitter() 1d=0q?nH
{ K3a>^g
return nSplitter; L-`(!j
} Q-M rH
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9)ACgz&(
public void setNSplitter(int nCount) aIQrb
{ !&'# a
nSplitter = nCount; k,a,h^{}j
} Lr K9F^c
} =|^X$H
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/* }*xC:A%aS
**Utility.java C<zx'lw!
*/ Z'voCWCd
package NetFox; 5Xp$yX =
9`OG
,G916J*XA
public class Utility { jK& Nkp
iSnIBs9\
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public Utility() 2q2p=H>&
{ ju8',ZC
&gY;`*<
THrc H
} (k7;
EG'7}W
//线程睡眠 i)A`Vpn
public static void sleep(int nSecond) _Cu[s?,kS
{ OI)&vQ5k
try{ *=($r%)
Thread.sleep(nSecond); ~5-~q0Ge
} pP?<[ql[w
catch(Exception e) ]s1TJw [B
{ Se!gs>
e.printStackTrace (); (1QdZD|
} _Ym&UY.u#
} *O"%tp6
!X \Sp}
//日志 c@0l-R{q
public static void log(String sMsg) ek Y?
{ nEjo,
System.err.println(sMsg); aL_;`@4
} ?AqrlR]5
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public static void log(int sMsg) 6Y0/i,d*
{ ?7rmwy\
System.err.println(sMsg); {jj]K.&
} ;`X`c
} J>,'P^
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v*vub#wP
/* D'HL /[@`
**TestMethod.java ` 4s#5g
*/ >=Rd3dgDG
package NetFox; &-EyM*:u!
B`'}&6jr.
?M*C*/R
public class TestMethod { 6/p]jN
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{[(W4NAlH
public TestMethod() r9p?@P\:[
{ ///xx/weblogic60b2_win.exe g7E`;&f
try{ ONg<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mvW^P`nB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MY0[Oq cm=
SiteFileFetch fileFetch = new SiteFileFetch(bean); +oxqS&$L
fileFetch.start(); FvtM~[Q
} jk WBw.(
catch(Exception e){e.printStackTrace ();} K-g=td/@
&;uGIk>s
baO&n
} VNOK>+
LN,$P
Zp% ""
public static void main(String[] args) @E&X&F%
{ f4@#pnJ3po
new TestMethod(); RPScP
} #/&q
} AOvH&9**
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