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)); o(BYT9|.kw
} 1.xw'i
for(int i=0;i<nEndPos.length-1;i++) ~91uk3ST?
{ wP+'04H0
nEndPos = nStartPos[i+1]; r]xdhR5
} s'_$j$1
nEndPos[nEndPos.length-1] = nFileLength; _6| /P7"
} s-y'<(ll
} C}|O#"t^\
I(F1S,7
T`j
//启动子线程 >2*6qx>V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; if\k[O 1T6
for(int i=0;i<nStartPos.length;i++) &Qz"nCvJ
{ 48W:4B'l9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _zAc 5rS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b49|4
nStartPos,nEndPos,i); E]D4']
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #{.pQi})
fileSplitterFetch.start(); =#J9
} Q2??Kp]1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8j({=xbg&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?yda.<"g9Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >!CH7wX
nEndPos = " + nFileLength); )yfOrsM
// fileSplitterFetch[nPos.length-1].start(); 'Sm/t/g"|
_AA`R`p;
%@)U/G6s}
//等待子线程结束 u9da]*\7y
//int count = 0; c1=;W$T(s
//是否结束while循环 a .B\=3xn
boolean breakWhile = false; m^(E:6T
zhD`\&G.
6oe$)iV
while(!bStop) ~W5>;6f\
{ m|g$'vjk
write_nPos(); %DHP
Utility.sleep(500); L8%=k%H(1
breakWhile = true; ant-\w>}
D<$j`r
LKoM\g(
for(int i=0;i<nStartPos.length;i++) K'ed5J
{ u^;sx/
if(!fileSplitterFetch.bDownOver) %6vMpB`g
{ P<g|y4h
breakWhile = false; _~(MA-l
break; kY0g}o'<
} AF07KA#
} Qt)7mf
if(breakWhile) $]`'Mi
break; ~%::r_hQ
S@l a.0HDA
%u<&^8EL+#
//count++; ueS[sN!
//if(count>4) U{.+*e18
// siteStop(); '{1W)X
} ;FIMCJS
yBD.Cs@
?`BED6$`G9
System.err.println("文件下载结束！"); &)/H?S;yN
} 3w6JV+?
catch(Exception e){e.printStackTrace ();} pU\xzLD
} zS>:7eG
}*{\)7g
8*Nt&`@
//获得文件长度 gs<qi'B
public long getFileSize() QvT-&|
{ Mf,Mcvs
int nFileLength = -1; tleK(^
try{ Z{|.xgsY
URL url = new URL(siteInfoBean.getSSiteURL()); 6H. L!tUI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lFzQG:k@
httpConnection.setRequestProperty("User-Agent","NetFox"); 5O4&BxQ~}
^me}k{x
ML9T(th6v
int responseCode=httpConnection.getResponseCode(); %`<`z yf
if(responseCode>=400) =QO1FO
{ WhVmycdv
processErrorCode(responseCode); 8u~\]1(
return -2; //-2 represent access is error Dk.9&9mz
} PK|`}z9
au9Wo<mR
%V" +}Dr
String sHeader; =G3J.S*Riy
D;T r
8-l)TTP&.
for(int i=1;;i++) QYCNO#*
{ O(sFs1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;V}FbWz^v6
//Utility.log(in.readLine()); \Lh<E5@]
sHeader=httpConnection.getHeaderFieldKey(i); zI*/u)48
if(sHeader!=null) qjRiTIp9q
{ `peJ s~V
if(sHeader.equals("Content-Length")) 'c+qBSDA
{ G5eLs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +#*z"a`
break; gQcr'[[a
} c75vAKZ2
} Xrzh*sp
else 1Mhc1MU
break; p?gLW/n
} aPP<W|Cmo2
} m^s2kB4A[
catch(IOException e){e.printStackTrace ();} b-=[(]_$h
catch(Exception e){e.printStackTrace ();} 5Vm}<8{
Q*J ~wuE2
8GAQVe^$-
Utility.log(nFileLength); D8Waf
qYrGe
,Vn]Ft?n
return nFileLength; r.G/f{=<@
} })u}PQ
%D6Wlf+^n
b2@x(5#
//保存下载信息（文件指针位置） RxeRO2
private void write_nPos() E@}j}/%'O
{ ?g*T3S"
try{ HG6{`i
output = new DataOutputStream(new FileOutputStream(tmpFile)); v{*X@)$
output.writeInt(nStartPos.length); >^ 1S26
for(int i=0;i<nStartPos.length;i++) 9@EnmtR
{ .A[.?7g
// output.writeLong(nPos); ?m7"G)
output.writeLong(fileSplitterFetch.nStartPos); *A9{H>Vq
output.writeLong(fileSplitterFetch.nEndPos); $YQ&\[pDA
} X@4d~6k?
output.close(); 1? hd
} ik NFW*p
catch(IOException e){e.printStackTrace ();} iiDkk
catch(Exception e){e.printStackTrace ();} $I]x &cF
} BRLU&@G`1
v@s`l#
tU2;Wb!Y
//读取保存的下载信息（文件指针位置） 2EcYO$R!
private void read_nPos() S_;:iC]B
{ !!#ale&
try{ Q+M3Pqy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kGeME
int nCount = input.readInt(); Kqu7DZ+W
nStartPos = new long[nCount]; uvM88#
nEndPos = new long[nCount]; =w?cp}HW
for(int i=0;i<nStartPos.length;i++) jCv+m7Z
{ sU!q~`; J
nStartPos = input.readLong(); x=+I8Q4:
nEndPos = input.readLong(); 54j $A
} @Odu.F1e
input.close(); Lcb59Cs6e
} `8bp6}OD,
catch(IOException e){e.printStackTrace ();} ,$[lOFs
catch(Exception e){e.printStackTrace ();} "G)? E|
} P.J}\;S T
0].5[Jo
7NqV*
private void processErrorCode(int nErrorCode) dju{&wo~4
{ MT gEq
System.err.println("Error Code : " + nErrorCode); V1qHl5"
} @V u[Tg}J
4Lb<#e13R?
jzp%.4/j
//停止文件下载 39eoL;O_
public void siteStop() h*%1Jkxu
{ Q{kuB+s
bStop = true; cIkLdh
for(int i=0;i<nStartPos.length;i++) |@|D''u>6
fileSplitterFetch.splitterStop(); w]XBq~KO
jGPs!64f)
*E6 p=
} ^jA^~h3(W
} ~vS.Dr
//负责部分文件的抓取 @@&;gWr;
**FileSplitterFetch.java -fn~y1
*/ d|lzkY~
package NetFox; _JoA=<O!
b5C #xxIO
~C+T|
import java.io.*; r]{:{Z
import java.net.*; sS|5x
wEyh;ID3#
L;<]wKs
public class FileSplitterFetch extends Thread { J{I?t~u
_uacpN/<|
vzPrG%Uu7g
String sURL; //File URL p};<l@
long nStartPos; //File Snippet Start Position +bU(-yRy5o
long nEndPos; //File Snippet End Position 7IRn
int nThreadID; //Thread's ID NU"X*g-x^
boolean bDownOver = false; //Downing is over >~k Y{_
boolean bStop = false; //Stop identical >d|W>|8e
FileAccessI fileAccessI = null; //File Access interface n"vI>_|G
U6"50G~u
lU3wIB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C_o.d~xm
{ F u)7J4Z
this.sURL = sURL; 1l{n`gR
this.nStartPos = nStart; hw1s^:|+2
this.nEndPos = nEnd; -)/>qFj)
nThreadID = id; +=v|kd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W%x#ps5%
} mJHX
"wc $'7M
w*x}4wW
public void run() L'(^[vR(
{ /on p<u
while(nStartPos < nEndPos && !bStop) O`4X[r1LD
{ 1Y_fX
v~SN2,h
5 ,HNb
try{ e3.TGv7=
URL url = new URL(sURL); |?8wyP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wp ]u0w
httpConnection.setRequestProperty("User-Agent","NetFox"); 3)sqAs(
String sProperty = "bytes="+nStartPos+"-"; - >2ej4C
httpConnection.setRequestProperty("RANGE",sProperty); 1*5n}cU~
Utility.log(sProperty); 3!I8J:GZ:
??4QDa-
+oc}kv,h]
InputStream input = httpConnection.getInputStream(); p[RD[&#b
//logResponseHead(httpConnection); G:UdU{
a v/=x
;:cM^LJ
byte[] b = new byte[1024]; NEvt71k
int nRead; z&eJ?wb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m1TPy-|1
{ 1BF+sT3
nStartPos += fileAccessI.write(b,0,nRead); _=rXaTp
//if(nThreadID == 1) zx^)Qb/EL6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RGcT
} $>+-=XMVB
yy9Bd>
*op7:o_
Utility.log("Thread " + nThreadID + " is over!"); 6;VlX,,j
bDownOver = true; 0]T ;{
//nPos = fileAccessI.write (b,0,nRead); BD#4=u
} dX<UruPA
catch(Exception e){e.printStackTrace ();} Z"P{/~HG
} SU*P@?:/}
} 8`*(lKiL
P9c1NX\-
/(Y\ <
//打印回应的头信息 b{(:'.
public void logResponseHead(HttpURLConnection con) E3`KO'v%
{ /8.;
for(int i=1;;i++) ,L`qV
{ X(bb1
String header=con.getHeaderFieldKey(i); :yv! x
if(header!=null) k(Ow.nkb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GG7N!eZ
Utility.log(header+" : "+con.getHeaderField(header)); 7"M7N^
else ^ K/B[8
break; fY>\VY$>
} B3K%V|;z )
} n6oVx5/
EQg 6*V
=uD2j9!"7
public void splitterStop() Vb/J`
{ A=BpB}b
bStop = true; t#kmtJC
} T `N(=T^*
ofS9h*wrJ
C}45ZI4
} m"u 9AOHk
K?P.1H`
#E>f.:)
/* d ;ry!X
**FileAccess.java ucTkWqG
*//文件访问(定位，写) NmK%k jCx
package NetFox; \,~gA
import java.io.*; ci,o'`Q
-^C;WFh8)
n_iq85
public class FileAccessI implements Serializable{ }Dk_gom_
n1$p esr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r/8,4:rh
RandomAccessFile oSavedFile; ZN^9w"A
long nPos; g~N)~]0{
hX_;gR&R
R(ay&f%E
public FileAccessI() throws IOException _Tev503
{ <PXA`]x~
this("",0); tWD*uAb
} ZO:{9vt=/
/ZX8gR5x
fFMG9]*
public FileAccessI(String sName,long nPos) throws IOException 3 nb3rHQ
{ r0?`t!%V
oSavedFile = new RandomAccessFile(sName,"rw"); .3oFSc`q
this.nPos = nPos; #kk_iS>8
oSavedFile.seek(nPos); 2qw~hWX
} >(*jL
LKztGfy
Onby=Y o6
public synchronized int write(byte[] b,int nStart,int nLen) (iH5F9WO
{ t:$p8qR
int n = -1; v||8Q\d
try{ mii9eZ
oSavedFile.write(b,nStart,nLen); aZ#c_Q#gZ
n = nLen; XgU]Ktl
} #>[+6y]U!
catch(IOException e) sLb[ZQ;j
{ H|==i2V{
e.printStackTrace (); g7#_a6
} znX2W0V
G,$RsP
O" n/.`
return n; LR'F/.Dx
} 866n{lyL
xs+MvXTC
MZ6?s(mkx
} 99H&#!~bSS
W/xb[w9v
&`0heJ 5Yn
/* FtT+Q$q=
**SiteInfoBean.java y~Sh|2x8v
*/ .Mdxbs6.C
package NetFox; XEY((VL0
!SKEL6~7
qtD3<iWV
public class SiteInfoBean { eB^:+h#A_
s3Y \,9\
x}].lTjD
private String sSiteURL; //Site's URL @tRq(*(/:
private String sFilePath; //Saved File's Path jo0p/5;
private String sFileName; //Saved File's Name 66Huqo
private int nSplitter; //Count of Splited Downloading File WwPfz<I
9^3y\@ m
d*7 Tjs{\
public SiteInfoBean() +Q8Bin
{//nSplitter的缺省值为5 X#Ajt/XQ
//default value of nSplitter is 5 sGc4^Z%l?
this("","","",5); +wgNuj0=*
} }I9\=jT
y!)Z ^u
5!NK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sn]8h2z
{ Tr-gdX ;
sSiteURL= sURL; 4JT9EKo
sFilePath = sPath; Y_xPr%%A
sFileName = sName; yv[s)c}
this.nSplitter = nSpiltter; <pK72
YJ_LD6PL9
P}KyT?X:
} 9=&LMjTQ
h7wm xa;
#,0%g1
public String getSSiteURL() k]] (I<2
{ uF+if`?
return sSiteURL; gV91=Pj
} ?Xx,[Z&
#-+!t<\
)K4 |-<i
public void setSSiteURL(String value) 9axJ2J'g
{ Y\Odj~Mj
sSiteURL = value; 4Sfv
} q1;}~}W;z4
7^A;.x
!=V>DgmW
public String getSFilePath() O\,n;oj
{ .>Gq/[c0|
return sFilePath; +FP*RNM
} 1NtN-o)N?
\`-/\N
Ysz{~E'
public void setSFilePath(String value) }:5AB93(
{ lUJ/ nG0l
sFilePath = value; =cs;avtL
} n\Uh5P1W"
qrsPY d
559znM=
public String getSFileName() cor?#
{ }eXzs_
return sFileName; &B1d+.+
} p6$ QTx
q g?q|W
OW<i"?0
public void setSFileName(String value) a;|C51GH
{ ZRf-V9
sFileName = value; 1a;Le8
} RLOB
B @H.O!
(D]l/akP
public int getNSplitter() HaXlc8
{ I8;pMr6
return nSplitter; aL$m
} .?UK`O2Q
5M4mFC6
]X?~Cz/wl
public void setNSplitter(int nCount) 6?b9~xRW
{ 7d*SZmD
nSplitter = nCount; dPwe.:
} zA=gDuy3@
} Qctm"g|
qRT1Wre 3
W|_ @ju
/* fo9O+e s
**Utility.java pRe, B'&
*/ Y[k%<f
package NetFox; -H5n>j0!{
Me;@/;c(
p(in.Xz
public class Utility { R}IMX9M=
; >Tko<
&@u;xc| v
public Utility() Z[<rz6%cB
{ A rC4pT
Y0fX\6=h
H6X]D"Y,
} zc>/1>?M
,TPNsz|Q
//线程睡眠 E5qh]z(
public static void sleep(int nSecond) ??0C"8:[
{ WW82=2rJ9
try{ S7&w r@
Thread.sleep(nSecond); *ci,;-*C
} "W$,dWF
catch(Exception e) H)S" `j
{ W}p>jP}
e.printStackTrace (); ;M}'\.
} ]vj=M-:+
} ^vmT=f;TM
:fz&)e9
//日志 8##-fv]
public static void log(String sMsg) LDqq'}qK6
{ T;K,.a8bU
System.err.println(sMsg); ovJ#2_
} qXPjxTg{[
CnyCEIO-
MUsF/1
public static void log(int sMsg) I:l<t*
{ nTxeV%
System.err.println(sMsg); dYV'<
} "\M16N
} 0; GnR0
_|qJ)gD[
S^0Po%d
/* }9yAYZ0q{b
**TestMethod.java $GhdH)
*/ %&m/e?@%I
package NetFox; oe,I vnt
R&}"En`$s
.w=( G
public class TestMethod { SXkUtY$
?u.&BP
G?D7R/0)
public TestMethod() h?E[28QB
{ ///xx/weblogic60b2_win.exe hbm%{*d
try{ a9S0glbwf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7x`dEi<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OI0#@_L&
SiteFileFetch fileFetch = new SiteFileFetch(bean); xG:eS:iT
fileFetch.start(); KW.*LoO
} /RD@ [ 8
catch(Exception e){e.printStackTrace ();} g-`HKoKe
^uB9EP*P
1OB,UU"S$
} N~7xj?
"FA&Qm0
+vOlA#t%Z
public static void main(String[] args) f P'qUN
{ Qvc "?yx8}
new TestMethod(); '&/ 35d9|*
} z}I=:
} *J[3f]PBmR
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