http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); o< )"\f/,
} 9g%1^$R
for(int i=0;i<nEndPos.length-1;i++) *4]u?R
{ 5q<cZ)v#&
nEndPos = nStartPos[i+1]; Y#aL]LxZE
} m/ D~D~
nEndPos[nEndPos.length-1] = nFileLength; %H)^k${
} IXjFK
} "cJ))v-'
}STTDq4
&6ymGo
//启动子线程 (<bYoWrK#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2bu,_<K.
for(int i=0;i<nStartPos.length;i++) <V[Qs3uo(
{ j!1 :+H_L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FM{^ND9x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 244[a] %&;
nStartPos,nEndPos,i); \mK;BWg)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q4y P\B
fileSplitterFetch.start(); =()Vrk|uK
} `kE ;V!n?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <8J_[ S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -BV8,1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }Gvu!a#R
nEndPos = " + nFileLength); G 6r2 "
// fileSplitterFetch[nPos.length-1].start(); d76nyQKK
`jHbA#sO
.}n-N #
//等待子线程结束 #gq!L
//int count = 0; I$0O4
//是否结束while循环 u~pBMg ,
boolean breakWhile = false; 4Tdp;n\F
yg@8&;bP`
4UxxmREx;
while(!bStop) }Fq~!D Ee
{ i!<1&{
write_nPos(); ^RI&`5g
Utility.sleep(500); SSQB1c
breakWhile = true; [r#m +R"N
TSKT6_IJw
[d?tf
for(int i=0;i<nStartPos.length;i++) S+ 3lX7
{ 73p7]Uo
if(!fileSplitterFetch.bDownOver) '.B5CQ
{ '< .gKo
breakWhile = false; |Cm6RH$(
break; ?hmuAgOtbh
} cjp~I/U
} ~K/_51O'
if(breakWhile) gyz_$T@x
break; dW5@Z-9
|!q,J
}?)U`zF)7}
//count++; *'cyFu$
//if(count>4) (V x2*Aw]
// siteStop(); OLZs}N+;]
} k>)Uyw$!
.<zN/&MXf
C=Tq/L w
System.err.println("文件下载结束！"); JfsvK2I
} ]!X[[w)
catch(Exception e){e.printStackTrace ();} Bra}HjHO
} 2!_DkE
Y#t9DhzFWo
oZ_,WwnE
//获得文件长度 m-2!r*(zt
public long getFileSize() ,m Nd#
{ TD sjNFe3
int nFileLength = -1; RT. %\)))
try{ YU`}T<;bg
URL url = new URL(siteInfoBean.getSSiteURL()); n-u HKBq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /K(l[M
httpConnection.setRequestProperty("User-Agent","NetFox"); /Un\P
< V*/1{
GOsOFs"I
int responseCode=httpConnection.getResponseCode(); skYHPwJdW
if(responseCode>=400) )UtK9;@"
{ R; ui 4wg6
processErrorCode(responseCode); T/PmT:Qg`
return -2; //-2 represent access is error QM'|k6
} \UP=pT@
\S_Ae;
0a2#36;_IK
String sHeader; V aoqI
^-Rqlr,F;
1k]L,CX
for(int i=1;;i++) "rrw~
{ {"2Hv;x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `GSl}A
//Utility.log(in.readLine()); DX^8w?t
sHeader=httpConnection.getHeaderFieldKey(i); K 6yD64
if(sHeader!=null) 'jXJ!GFw
{ ;9Qxq]
if(sHeader.equals("Content-Length")) @?jbah#
{ azzG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oE_*hp+
break; 2tg07
} }mo)OyIX
} }KYOde@
else _f~$iY
break; xSqr=^
} KF1Zy;
} lvRTy|%[
catch(IOException e){e.printStackTrace ();} njaKU?6%d2
catch(Exception e){e.printStackTrace ();} #Cx#U"~G`
M~h.MPI
CED[\n
Utility.log(nFileLength); Z&4L///
]a`"O
YhzDw8f
return nFileLength; 8;"9A
} ;Ea8>
}]M'f:%b
;n.h!wmJ}
//保存下载信息（文件指针位置） F vTswM>
private void write_nPos() z7z9lDS
{ H )>3c1
try{ HRJ\H- V
output = new DataOutputStream(new FileOutputStream(tmpFile)); B873UN
output.writeInt(nStartPos.length); r,3\32[?
for(int i=0;i<nStartPos.length;i++) ?D,j!Hy
{ D>^g2!b:
// output.writeLong(nPos); XZS%az1%
output.writeLong(fileSplitterFetch.nStartPos); ;at1|E*
output.writeLong(fileSplitterFetch.nEndPos); '? -N
} x}O,xquY
output.close(); .beqfcj"
} &*E! %57
catch(IOException e){e.printStackTrace ();} 2.=G
catch(Exception e){e.printStackTrace ();} zk!7TUZ">w
} WJ)4rQ$o
sxS%1hp3
k ]T
//读取保存的下载信息（文件指针位置） jse!EtB:
private void read_nPos() WgG$ r
{ Um4DVg5
try{ $RB p!7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0rQr#0`
int nCount = input.readInt(); "'GhE+>Z
nStartPos = new long[nCount]; Q, "8Ty
nEndPos = new long[nCount]; f& \Bs8la
for(int i=0;i<nStartPos.length;i++) ]5K(}95&'
{ *z#du*f[
nStartPos = input.readLong(); )m[<lJbw
nEndPos = input.readLong(); ^fyue~9u
} ,KD?kSIf
input.close(); |lZJt
} Fa\jVFIQ
catch(IOException e){e.printStackTrace ();} ?Z4%u8Krvz
catch(Exception e){e.printStackTrace ();} Vy|4k2
} Rry]6(
-rjQ^ze
k4!_(X%8
private void processErrorCode(int nErrorCode) V1GkX=H},
{ 4*9t:D|}
System.err.println("Error Code : " + nErrorCode); lzz;L z
} )v11j.D
ms!|a_H7r
ywkRH
//停止文件下载 m2YsE j7
public void siteStop() U* c'xoP
{ fLd2{jI,
bStop = true; Rjlp<
for(int i=0;i<nStartPos.length;i++) r b\t0tg
fileSplitterFetch.splitterStop(); 2_6ON
h:U#F )
aG]^8`~>'
} }%jpqip
} 1X`,7B@pz
//负责部分文件的抓取 bq8Wvlv04
**FileSplitterFetch.java >M!LC
*/ Jw&Fox7p
package NetFox; Ziub%C[oV
(fr=N5
^c>Bh[
import java.io.*; ;"ESN)*|i
import java.net.*; ]NI CQ9
<5 OUk
:vx<m_
public class FileSplitterFetch extends Thread { T9!NuKfur
om9'A=ZU
lKQevoy'
String sURL; //File URL c#`IF6qj
long nStartPos; //File Snippet Start Position dFhyT.Y?
long nEndPos; //File Snippet End Position m[iQ7/
int nThreadID; //Thread's ID md? cvGDE
boolean bDownOver = false; //Downing is over #qR6TM&;
boolean bStop = false; //Stop identical 5XzsqeG|
FileAccessI fileAccessI = null; //File Access interface A+frKoi
ZZHzC+O#^
Iz'Et'w8!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sKsMF:|OT
{ @iXBy:@
this.sURL = sURL; a j$& 9][
this.nStartPos = nStart; ?*yB&(a:8
this.nEndPos = nEnd; aI;$N|]u
nThreadID = id; QtXiUx^ k<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vD:J!|hs(
} :ir3u
YTmHht{j#
\%bJXTK&W
public void run() @Tq-3Um
{ Lj#xZ!mQS
while(nStartPos < nEndPos && !bStop) qO8:|q1%;\
{ V/#J>-os}W
Iz j-,a
5 r_Z3/%
try{ 6&0G'PMf
URL url = new URL(sURL); +]( y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?6nB=B)/
httpConnection.setRequestProperty("User-Agent","NetFox"); zS|4@t\__
String sProperty = "bytes="+nStartPos+"-"; JC-> eY"O2
httpConnection.setRequestProperty("RANGE",sProperty); C& XPn;f
Utility.log(sProperty); L-S5@;"
_KkaseR
XqUQ{^;aI
InputStream input = httpConnection.getInputStream(); ov H'_'
//logResponseHead(httpConnection); izGU&VeB
b]Kb ~y|
<uJ {>~
byte[] b = new byte[1024]; 3!/J!X3L
int nRead; TQNdBq5I6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5}Ge
{ +!px+*)bW
nStartPos += fileAccessI.write(b,0,nRead); "v`q%(TA
//if(nThreadID == 1) *i#N50k*j'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (|o@
} $gz8! f?
4F0w+wJD
z;2& d<h
Utility.log("Thread " + nThreadID + " is over!"); yufw}Lo-
bDownOver = true; .d[^&<^
//nPos = fileAccessI.write (b,0,nRead); );TB(PQsBT
} %mU$]^Tw(
catch(Exception e){e.printStackTrace ();} P]y{3y:XxM
} NIQ}+xpC
} F%&lM[N%
":qHDL3
C;/ONF
//打印回应的头信息 &8Vh3QLEx
public void logResponseHead(HttpURLConnection con) 1y6<gptx
{ ^E\n^D-RV
for(int i=1;;i++) Bhx.q,X
{ ~vA8I#.
String header=con.getHeaderFieldKey(i); *S}CiwW>/
if(header!=null) islHtX VE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x7^VU5w#
Utility.log(header+" : "+con.getHeaderField(header)); qUmSB"#Z
else a?GXVQ
break; m-tn|m!J
} H Q[
} Opg_-Bf
||TZ[l
?SO!INJ
public void splitterStop() j7a}<\
{ O/ItN5B ;
bStop = true; st)v'ce,
} %g5#q64
>b9J!'G,(
5[B)U">]
} OvwoU=u
[bX^_ Y
FW;}S9u3
/* SB('Nqih
**FileAccess.java }|) N5bGQe
*//文件访问(定位，写) L aA<`
package NetFox; .{?;#Cdn
import java.io.*; PZ'|)
%(6+{'j~#
BQ[R)o
public class FileAccessI implements Serializable{ 9ei'oZ
B=^M& {
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g@M5_I(W
RandomAccessFile oSavedFile; :8}Qt^p
long nPos; e:4,rfF1
kCz2uG)l
i?@7>Ca
public FileAccessI() throws IOException 3Rsrb
{ TC'SDDX
this("",0); v^Fu/Y
} 33eOM(`D[
{6Nbar@3
Gl3g.`X{$@
public FileAccessI(String sName,long nPos) throws IOException 5eFtcK
{ dQ_'8 )
oSavedFile = new RandomAccessFile(sName,"rw"); \Wppl,"6c
this.nPos = nPos; s?1Aj<
oSavedFile.seek(nPos); l?m 3*
} jpR]V86G
'x?|tKzd
8p}z~\J{a:
public synchronized int write(byte[] b,int nStart,int nLen) .`J*l=u$
{ [h' 22W
int n = -1; iK1{SgXrFI
try{ D,FgX/&i/
oSavedFile.write(b,nStart,nLen); Ygg(qB1q
n = nLen; .}+3A~
} 4$N,|bt
catch(IOException e) #wvGS%
{ ^e =xEZD
e.printStackTrace (); m432,8 K3r
} =)i^E9
+gBDE:
3^q9ll7Op
return n; =Ov,7<8o
} Y4,p_6aKJ]
Zg4wd/y?
eej#14&
} tx+P@9M_Aq
eDNY|}$}v
8<Yv:8%B6
/* 4PU@W o
**SiteInfoBean.java lY,9bSF$
*/ MDd2B9cy[
package NetFox; 3qNuv];2
@RoU
@ZV>Cl@%2
public class SiteInfoBean { ?,hGKSC
KlBT9"6"
AtAu$"ue
private String sSiteURL; //Site's URL ]:?hU^H]<
private String sFilePath; //Saved File's Path n36@&q+B&
private String sFileName; //Saved File's Name \sW>Y#9]
private int nSplitter; //Count of Splited Downloading File ~e){2_J&n
+8|Xj!!*}
,~l4-x.,
public SiteInfoBean() | ObA=[j
{//nSplitter的缺省值为5 )B~{G\jS
//default value of nSplitter is 5 @fVz *
this("","","",5); 'q8:1i9\[
} }ri7@HCY4
irB}h!@
;\/RgN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {K/xI
{ ;1TQr3w
sSiteURL= sURL; <<YH4}wZ
sFilePath = sPath; |oR{c%z05
sFileName = sName; Zjc0R
this.nSplitter = nSpiltter; "88<{xL
2&o3OKt
S^i<_?nwg
} =}SC .E\
bD1IY1
2)q$HUIX
public String getSSiteURL() nqcD#HUv
{ = o1&.v2j
return sSiteURL; >lO]/3j1
} P>*`<$FR
w~e$ul(IQM
Jy]}'eE?pr
public void setSSiteURL(String value) M>jk"*hA|
{ ?SoRi</1
sSiteURL = value; 6bbzgULl
} nh"LdHqiDB
`hU2Ss~
QUc&f+~
public String getSFilePath() ^JB5-EtL(
{ }/%^;@q;
return sFilePath; 2wYY0=k2
} D}pNsQ
lXrAsm$
'c/Z W
public void setSFilePath(String value) H3BMN}K~
{ m'L8z fX
sFilePath = value; J|WkPv2
} /p[lOg
SBG.t:
Z<[f81hE&
public String getSFileName() _/a8X:[(
{ 6^Ax3#q
return sFileName; :*E#w"$,j
} "]1|%j
`bRt_XGPmF
]1i1_AR'`
public void setSFileName(String value) N51RBA
{ K<D=QweOon
sFileName = value; !>QD42
} '0E^th#u-0
A>Oi9%OY:
vip& b}u
public int getNSplitter() CXhE+oS5z'
{ H7R6Ljd?&S
return nSplitter; $_0~Jzt,
} Ni)/L( &
81/t)Cp
Z3Y(g
public void setNSplitter(int nCount) c/ABBvd|
{ m}>#s3KPA
nSplitter = nCount; }6^d/nE*T
} t"L-9kCM
} aMycvYzH
-H(\[{3{V
d#]XyN>
/* lDm0O)Dh!
**Utility.java Hwm]l`E]
*/ A +J&(7N
package NetFox; ~^pV>>LX|
[qGj*`@C
bB`p-1
public class Utility { %nkP?gn"a
('7qJkV
c$[cDf~
public Utility() Qt+;b
{ c O[Hr
\ZPmPu9^(
7`IoQvX
} BYBf`F)4
%qf ?_2v
//线程睡眠 Tf1G827
public static void sleep(int nSecond) G`1FD
{ r#CQCq
try{ o> i`Jq&
Thread.sleep(nSecond); vw/L|b7G
} a J&)-ge
catch(Exception e) @L ,hA v^
{ |wFfVDp
e.printStackTrace (); fxKhe[;
} k;bdzcMkQ
} QC+K:jL
A/zZ%h
//日志 O!7v&$]1
public static void log(String sMsg) @!UuK;
{ nA#FGfZ{Ge
System.err.println(sMsg); :t36]NM
} bm+ #OI
KkJK5dZo
=83FCq"
public static void log(int sMsg) L\u6EMyV
{ ;n)9
System.err.println(sMsg); nYc8+5CcK'
} */ ~_3
} vl{G;[6
XsVp7zk\
TC%ENxDR
/* ]N\J~Gm
**TestMethod.java 6!eI=h2P
*/ X?'v FC
package NetFox; ,a&&y0,
Sl?@c/Ng
k_^|%xJ
public class TestMethod { X<OOgC
g=T !fF=
k{?Pgf27
public TestMethod() /i${[1
{ ///xx/weblogic60b2_win.exe [-*1M4D9
try{ ># {,(8\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2,nVo^13}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1${lHVx]
SiteFileFetch fileFetch = new SiteFileFetch(bean); wstH&^
fileFetch.start(); Oc|`<^m
} )_vE"ryThA
catch(Exception e){e.printStackTrace ();} 23F<f+2S
v7i5R !
/qYo*S_cG
} /ynvQ1#uA
XpFoSW#K
jP]I>Tq
public static void main(String[] args) ^X&n-ui
{ ymIjm0jVh
new TestMethod(); ^sWsP`DV
} _x.<Zc\x
} KNkVI K
点击下载更多相关资料