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)); 0s'h2={iI
} bpgvLZb>s
for(int i=0;i<nEndPos.length-1;i++) "kS!rJ[
{ s:ZYiZ-
nEndPos = nStartPos[i+1]; k3yA*Ec
} `WRM7
nEndPos[nEndPos.length-1] = nFileLength; $s.:H4:I
} j0`)mR}
} ;vuqI5k
,$A'Y
hb="J349
//启动子线程 =`pH2SJT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z&KrG
for(int i=0;i<nStartPos.length;i++) iKM!>Fi
{ #AO?<L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0(|Yy/Yq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rHaj~s 4
nStartPos,nEndPos,i); )sZJH9[K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?DrA@;IB
fileSplitterFetch.start(); =8V 9E
} \@!"7._=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hH(w O\s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Nbvs_>N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HE|XDcYO
nEndPos = " + nFileLength); KBOp}MEz
// fileSplitterFetch[nPos.length-1].start(); !*G%vOa
N(Sc!rX
+oevNM
//等待子线程结束 slTE.
//int count = 0; q/#pol
//是否结束while循环 J:Idt}@z
boolean breakWhile = false; N}gPf i
SUC'o"
fvBL? x
while(!bStop) f"RS,]
{ 4..M *U
write_nPos(); [JVEKc ym
Utility.sleep(500); ORx6r=zg
breakWhile = true; qd<-{
Lvd es.0|
cNl NJ
for(int i=0;i<nStartPos.length;i++) L+.&e4f'oj
{ E< Y!BT[X
if(!fileSplitterFetch.bDownOver) q>rDxmP<
{ 6m%#cP (6K
breakWhile = false; YN}vAFR`
break; 38#Zlcf
} 8_Nyy/K#F
} \@B'f
if(breakWhile) G_]zymXQ
break; o]M1$)>b+
lc[)O3,,B
(L<qJd1Q
//count++; G _-JR
//if(count>4) hN^,'O
// siteStop(); .]w=+~h
} K1$
F}~qTF;H
vzFo"
System.err.println("文件下载结束！"); 0,whTnH|
} dym K@
catch(Exception e){e.printStackTrace ();} }0V aZ<j
} 4w5);x.
#w@V!o
Qo~|[]GE
//获得文件长度 J'C9}7G
public long getFileSize() =}g-N)^
{ mg]t)+PQ
int nFileLength = -1; !nU|3S[b
try{ 4;*jE (
URL url = new URL(siteInfoBean.getSSiteURL()); HtV8=.^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N 9W,p2
httpConnection.setRequestProperty("User-Agent","NetFox"); rS8}(lf
ykYef
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int responseCode=httpConnection.getResponseCode(); YeS5%?Fk
if(responseCode>=400) s}F.D^^G
{ 1ixBwnp?
processErrorCode(responseCode); wxo*\WLe
return -2; //-2 represent access is error MY}/h@
} A{p_I<
Du #>y!
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String sHeader; c] -
+ib&6IU
(q@%eor&}
for(int i=1;;i++) hg2Ywzfm-
{ 2]]}Xvx4#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h~lps?.#b
//Utility.log(in.readLine()); ot0g@q[3
sHeader=httpConnection.getHeaderFieldKey(i); GkpYf~\Q
if(sHeader!=null) n^|SN9_r
{ K0~=9/
if(sHeader.equals("Content-Length")) ^8KxU
{ SQ&}18Z~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iURSYR
break; [y~kF?a
} d uP0US
} NvC @
else "U!Vdt2vp
break; =~k}XB
} #(QS5J&Qq
} 0t[ 1#!=k
catch(IOException e){e.printStackTrace ();} pgQ^w0BQV
catch(Exception e){e.printStackTrace ();} ^5Zka!'X2Z
@/,0()*dL
7g$*K0m`
Utility.log(nFileLength); Y-lwS-Ii
x_t$*
^WF_IH&
return nFileLength; W_6gV
} %l,CJd5
7K ~)7U
Hy5 6@jW+E
//保存下载信息（文件指针位置） 6LrI,d
private void write_nPos() _Wq;bKG
{ 31\mF\{V
try{ Zv2]X-
output = new DataOutputStream(new FileOutputStream(tmpFile)); G5%k.IRz
output.writeInt(nStartPos.length); _0BQnzC=
for(int i=0;i<nStartPos.length;i++) jn`5{ ]D
{ #"8'y
// output.writeLong(nPos); z%BX^b$Hj
output.writeLong(fileSplitterFetch.nStartPos); E@EP9X >
output.writeLong(fileSplitterFetch.nEndPos); &c}2[=
} M3Qi]jO98
output.close(); I@5$<SN
} YC$>D?FW
catch(IOException e){e.printStackTrace ();} K4-_a{)/
catch(Exception e){e.printStackTrace ();} 0"Euf41
} cc3/XBo
w/:ibG@
e,Z[Nox
//读取保存的下载信息（文件指针位置） zJ$U5r/u
private void read_nPos() <,Pl31g^
{ l[i1,4
try{ [+8*}03
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K:A:3~I!NW
int nCount = input.readInt(); 9kwiG7V1
nStartPos = new long[nCount]; Nv|0Z'M
nEndPos = new long[nCount]; f|ERZN`uB
for(int i=0;i<nStartPos.length;i++) \GV'{W+o2
{ %mIdQQ,
nStartPos = input.readLong(); u@P1`E1Q
nEndPos = input.readLong(); OsW*@v(
} 8 &v)Vi-
input.close(); &O#1*y Z
} RP^vx`9h
catch(IOException e){e.printStackTrace ();} QyY<Zi;6
catch(Exception e){e.printStackTrace ();} sgnc$x"
} @^J>. g
sy-#Eo#3
)c?nh3D
private void processErrorCode(int nErrorCode) 4;@L#Pzt
{ Z +O<IF%
System.err.println("Error Code : " + nErrorCode); <EdNF&S-
} w+Gav4
2R ^6L@fw
_0ZU I^#
//停止文件下载 k)[c!\a[i
public void siteStop() R<vbhB/lU
{ GHo mk##0E
bStop = true; u/NcX
for(int i=0;i<nStartPos.length;i++) B~M6l7^?
fileSplitterFetch.splitterStop(); =p7id5"
XL9-N?(@
fQwLx
} \/C5L:|p_
} wCV~9JTJ!
//负责部分文件的抓取 u?rX:KkS
**FileSplitterFetch.java fdHFSnQ g
*/ ~]`U)Aw
package NetFox; d(:I~m
kZ]pV=\Y*
;@:-T/=
import java.io.*; jP0TyhM
import java.net.*; eKLE^`2*@
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Ck>]+rl
public class FileSplitterFetch extends Thread { #3{{[i(;i
4#.Q|vyl]"
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String sURL; //File URL P!IXcPKW53
long nStartPos; //File Snippet Start Position 2aX{r/Lc
long nEndPos; //File Snippet End Position )=bW\=[8
int nThreadID; //Thread's ID (^B=>
boolean bDownOver = false; //Downing is over ?>I
boolean bStop = false; //Stop identical V6h8+|hK
FileAccessI fileAccessI = null; //File Access interface ks %arm&
r:Q=6j,
3.g4X?=zd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $dWYu"2CD
{ ~;YkR'q0_
this.sURL = sURL; kBnb9'.A1
this.nStartPos = nStart; Rlm28
this.nEndPos = nEnd; 8H T3C\$s
nThreadID = id; +F%tBUY{<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ct zWdo.
} .JJ50p
"zzb`T[8
~=t9-AF-
public void run() hs:iyr]@9
{ ie>mOsz
while(nStartPos < nEndPos && !bStop) 8J- ?bo
{ Z6Z/Y()4Tl
xP;>p| M
FFe{=H,=
try{ @?;)x&<8?3
URL url = new URL(sURL); JoZzX{eu"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :Bu)cy#/[
httpConnection.setRequestProperty("User-Agent","NetFox"); _meW9)B
String sProperty = "bytes="+nStartPos+"-"; :7JP(j2
httpConnection.setRequestProperty("RANGE",sProperty); rx@i.+
Utility.log(sProperty); !,rF(pz
D~|q^Ms,%
5*Qzw[[=
InputStream input = httpConnection.getInputStream(); Y7 K2@257
//logResponseHead(httpConnection); k7L4~W
rz2,42H]
jGo\_O<of
byte[] b = new byte[1024]; qn,fx6v4
int nRead; +x/vZXtOK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :#{0yno)H
{ Iz;^D!
nStartPos += fileAccessI.write(b,0,nRead); Q`Q"p
//if(nThreadID == 1) `*`ZgTV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #l.s>B4
} OECVExb@eH
=vriraV"
A:(qF.Tm
Utility.log("Thread " + nThreadID + " is over!"); QFoCi&
bDownOver = true; X?JtEQ~>
//nPos = fileAccessI.write (b,0,nRead); p,uM)LD
} Q`4Ia<5B
catch(Exception e){e.printStackTrace ();} T&bB8tQk
} a<>cbP
} l<ZHS'-;8
2R^Eea
s8qpK; O
//打印回应的头信息 Fpwhyls
public void logResponseHead(HttpURLConnection con) rY1jC\
{ @xso{$z?j
for(int i=1;;i++) eb6y-TwY
{ {ot6ssT=D
String header=con.getHeaderFieldKey(i); ~?)y'?
if(header!=null) AMO{ee7Po
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L|1~'Fz#w
Utility.log(header+" : "+con.getHeaderField(header)); tL1\q Qg
else [Ls%nz|
break; /TIt-c
} ,_D@ggL-
} )7Qp9Fxo
/11CC \
q|IU+r:! 3
public void splitterStop() (?lT @RY/
{ yJlRW!@&:
bStop = true; +^J;ic
} '"ze Im~
5B8fz;l= B
jqTK7b
} ">S1,rhgS
w\V<6_[vv.
aSJD'u4w.a
/* kho0@o+'^
**FileAccess.java "gDk?w
*//文件访问(定位，写) JE*?O*&|Q
package NetFox; :<0lCj
import java.io.*; wyAh%'V
p6)6Gcx
oYJ<.Yxeb
public class FileAccessI implements Serializable{ cf*~Gx_l
JS<w43/j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ad>@8^
RandomAccessFile oSavedFile; $?VYHkX
long nPos; qLKL*m
QA)"3g
nrXKS&6
public FileAccessI() throws IOException "GJ.`Hj
{ YB^m!A),I[
this("",0); ~XvMiWuo
} "-AFWWKtx
1|>bG#|
f9IqcCSW
public FileAccessI(String sName,long nPos) throws IOException V>UlL&V
{ MU:v& sk
oSavedFile = new RandomAccessFile(sName,"rw"); ;vWJOvM2
this.nPos = nPos; {~(XO@;b
oSavedFile.seek(nPos); -rHqU|
} fZJM'+J@A
77 Z:!J|
#T`1Z"h<
public synchronized int write(byte[] b,int nStart,int nLen) I?%#`Rvu
{ iU=:YPE+.
int n = -1; u09D`QPP]
try{ +>c%I&h}`
oSavedFile.write(b,nStart,nLen); +#A~O4%t
n = nLen; Q7UQwAN'
} beV+3HqB8
catch(IOException e) DiZv sc
{ #!_ViG )2^
e.printStackTrace (); ="Azg8W
} <A`SC;k\u
r?pFc3~N
Z-" NLwt[
return n; iuM ,aF
} 2n#H%&^?a
}/IP\1bG
(hRg0Z=
} 1 .o0"
sqRvnCD!
,ZO?D|M1
/* XB:E<I'q!3
**SiteInfoBean.java hQvI}
*/ V{\1qg{
package NetFox; T$;BZ=_
ygK,t*T20
W&3,XFnI_
public class SiteInfoBean { 1:u~T@;" `
XXD4T9Wy
J'L6^-gV
private String sSiteURL; //Site's URL SaRn>n\
private String sFilePath; //Saved File's Path +HD2]~{EkL
private String sFileName; //Saved File's Name U><$p{)
private int nSplitter; //Count of Splited Downloading File gzlRK^5
"-G7eGQ
$H/: -v
public SiteInfoBean() Tl?jq]
{//nSplitter的缺省值为5 ,.;{J|4P
//default value of nSplitter is 5 O >@Q>Z8W?
this("","","",5); :SZi4:4-J8
} i.FdZN{
xsvJjs;=
V,?])=Ax
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DV*e.Y>
{ GK3cQw
sSiteURL= sURL; :01B)~^
sFilePath = sPath; @Yw42`>!s
sFileName = sName; e{^lD.E
this.nSplitter = nSpiltter; _5OxESE
bJeF1LjS
Sg\+al7
} SxkY ;^-U
&7{yk$]*
zIr-Rx'dL^
public String getSSiteURL() &F'n >QT9q
{ M`)3(|4
return sSiteURL; EQ"+G[j~x
} Z8f?uF
zP|^@Homk
r*FAUb`bG
public void setSSiteURL(String value) \(zUI
{ X'xnJtk
sSiteURL = value; QVl"l'e8
} _!?a9
iWkC:fQz
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public String getSFilePath() ],'"iVh
{ dMI G2log
return sFilePath; ~Ds3-#mMy
} {qs>yQ6a:-
3aJYl3:0B
}5Km \OI
public void setSFilePath(String value) @jZ1WHS_a
{ f'Oj01[
sFilePath = value; \GK]6VW
} ZJ/K MW
Nkn2\w
#TB 3|=
public String getSFileName() /#?!9c
{ pTH5-l_f]
return sFileName; :g+wv}z
} MaF4lFmS
CWb*bw0
/HdjPxH
public void setSFileName(String value) ^#4<~zU
{ on1B~?*D
sFileName = value; 3A.lS+P1
} :+8qtIytKX
{?r5~T`2
Sj viH
public int getNSplitter() uu/2C \n}
{ Ve xxdg
return nSplitter; j&q%@%Gm
} | _nBiHjNn
TrQUhmS/!
~CHVU3
public void setNSplitter(int nCount) *De'4r 2
{ BP1<:T'.q`
nSplitter = nCount; &@w0c>Y
} t"vkd
} w=5<mw
mgb+HNH%q\
h:KEhj\d?
/* !bCaDTz
**Utility.java h&rZR`g
*/ Q9&H/]"v
package NetFox; fGWXUJ
~{pds
"kjSg7m*:
public class Utility { s|k&@jH)
TK0W=&6#A
OMBH[_
public Utility() x }]"jj2x
{ D J7U6{KLq
wVc^l
bKEiS8x
} 9|m:2["|?
jVqpokWH
//线程睡眠 K{ntl-D&y
public static void sleep(int nSecond) wEQZ9?\
{ msQ?V&+<
try{ LG??Q+`l
Thread.sleep(nSecond); bL5u;iy)
} ?.Ip(g
catch(Exception e) %l!-rXp
{ ZVrZkd`
e.printStackTrace (); >Sb3]$$
} s@6Jz\<E
} "/%o'Fq
2WE01D9O
//日志 1*.*\4xo
public static void log(String sMsg) o/& IT(v
{ Lb{.}
System.err.println(sMsg); m^w{:\p
} w:mm@8N
ZKM@U?PK
#$}A$sm
public static void log(int sMsg) 5=8t<v1Bn
{ yR"mRy1
System.err.println(sMsg); lNTbd"}$:
} 5qFHy[IA
} ZH~Wn#Wp
DcE4r>8B
|7${E^u
/* #aiI]'
**TestMethod.java X8wtdd]64
*/ KN>h*eze
package NetFox; D ,[yx='
/QQjb4S}
RiFUa $
public class TestMethod { T`9nY!
6h0}ZM
%pqB/
public TestMethod() Zay%QNsb
{ ///xx/weblogic60b2_win.exe $EzWUt
try{ {d.K)8\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ls~9qkAyLx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #)3 B
SiteFileFetch fileFetch = new SiteFileFetch(bean); (6b0rqPF
fileFetch.start(); /U`p|M;
} }daU/
catch(Exception e){e.printStackTrace ();} Wfy+9"-;s
l=x(
/!qP=ngw9
} }(,{^".[}
P'DcNMdw
mu5r4W47
public static void main(String[] args) lS#^v#uS
{ =^\?{oV
new TestMethod(); /_YTOSZjm
} y|zIuI-p
} >]o>iOz;]
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