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)); 1KYN>s:
} &-1./?
for(int i=0;i<nEndPos.length-1;i++) XTDE53Js&
{ hGf-q?7
nEndPos = nStartPos[i+1]; ^<0IB#dA
} F.)!3YE
nEndPos[nEndPos.length-1] = nFileLength; ?R5'#|EyX
} D0;tcm.$
} >x[`;O4
ap}5ElMR
#'hLb
//启动子线程 LihjGkj\g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Fpt-V
for(int i=0;i<nStartPos.length;i++) M)cGz$Q|
{ 9B)(>~q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -s$<Op{s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vdn.)ir~P
nStartPos,nEndPos,i); +[m8c){
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x"(9II*
fileSplitterFetch.start(); a)2yE,":
} JLb6C52
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s T3p>8n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a-n4:QT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c#b:3dXx9
nEndPos = " + nFileLength); 0p fnV%
// fileSplitterFetch[nPos.length-1].start(); `dJDucD
S2~@nhO`U(
F3ZxhkF
//等待子线程结束 ~DLIzg7p!
//int count = 0; xfSG~csoz
//是否结束while循环 -PAF p3w\y
boolean breakWhile = false; jnoL2JR[=-
9e<Zgr?N
m%QqmTH
while(!bStop) C4$/?,K(
{ w 7tC|^#G
write_nPos(); f|xLKcOP
Utility.sleep(500); ~hURs;Sb
breakWhile = true; S2$5!(P
"7?js $
gZ(O)uzv
for(int i=0;i<nStartPos.length;i++) 6CNS%\A
{ )-&nxOP
if(!fileSplitterFetch.bDownOver) ~SVQ;U)-
{ {e]NU<G ,
breakWhile = false; BV9*s
break; q|q::q*
} K="I<bK
} p[YWSjf
if(breakWhile) (Cj,\r
break; 5_G'68;OV
X*Z5 P
?^3B3qqh9
//count++; XUsy.l/
//if(count>4) I=YCQ VvA
// siteStop(); *1;23BiH-
} 4]UT+'RubX
",Wf uz
\ j]~>9
System.err.println("文件下载结束！"); 11*"d#
} P`sN&Y~m
catch(Exception e){e.printStackTrace ();} Y}/jR6hK
} dy_.(r5[L]
h}6b&m
~'f8L#[M
//获得文件长度 #v qz{R~nM
public long getFileSize() |'@[N,
{ Xr2J:1pgg
int nFileLength = -1; X'2Gi
try{ OQ|,-
URL url = new URL(siteInfoBean.getSSiteURL()); gY\mXM*^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m9g^ -X
httpConnection.setRequestProperty("User-Agent","NetFox"); ocP*\NR
)b (X
aa=b<Cd
int responseCode=httpConnection.getResponseCode(); 8g5.7{ky
if(responseCode>=400) 0(vdkC4\A
{ )GCLK<,swu
processErrorCode(responseCode); 3qcpf:
return -2; //-2 represent access is error !ZA}b[
} ^HoJ.oC/
lDU#7\5.
#x|VfN5f
String sHeader; d:3= 1x
sBB:$X
iXnx1w
for(int i=1;;i++) 4i96UvkZ
{ Vdy\4 nu(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "{6KZ!+0
//Utility.log(in.readLine()); (T2<!&0 @
sHeader=httpConnection.getHeaderFieldKey(i); =KW|#]RB^
if(sHeader!=null) wJr/FE7c
{ k#-[ M.i
if(sHeader.equals("Content-Length")) L]a|vp
{ sK[Nti0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6%z`)d
break; vy:6_
} )rS^F<C
} td`wNy\
else I$F\(]"@
break; `C ?a
} s~#?9vW
} np&HEh 6
catch(IOException e){e.printStackTrace ();} <|wmjW/D
catch(Exception e){e.printStackTrace ();} \J\vp0[nO}
dfXV1B5
=I{S;md
Utility.log(nFileLength); OHQ3+WJ
lTd+{TF.
EywZIw?mjX
return nFileLength; *E$H;wKs8
} ~V|KT}H
g9! dpP
#0xm3rFy4
//保存下载信息（文件指针位置） d9ZDpzxB
private void write_nPos() 9eksCxFg
{ $d5&~I
try{ ; \Y-
output = new DataOutputStream(new FileOutputStream(tmpFile)); !Q\X)C
output.writeInt(nStartPos.length); %Tk}sfx
for(int i=0;i<nStartPos.length;i++) p3i qW,[@
{ 2I9{+>k
// output.writeLong(nPos); InTKdr^ P
output.writeLong(fileSplitterFetch.nStartPos); AJdlqbd'+
output.writeLong(fileSplitterFetch.nEndPos); b'i%B9yU:%
} ,|=iv
output.close(); W"#j7p`d
} GIJV;7~
catch(IOException e){e.printStackTrace ();} 9p!dQx
catch(Exception e){e.printStackTrace ();} 0^_)OsFA
} JT}dor
9QO!vx
+/1P^U /
//读取保存的下载信息（文件指针位置） r5<e}t-
private void read_nPos() V1AEjh
{ #0#V$AA>
try{ xQcMQ{&;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "y3dwSS
int nCount = input.readInt(); u:p:*u_^I
nStartPos = new long[nCount]; ,(5dQ`hA0
nEndPos = new long[nCount]; 70I4-[/z[d
for(int i=0;i<nStartPos.length;i++) ~%::r_hQ
{ rYP8V >
nStartPos = input.readLong(); RJ7/I/yD|
nEndPos = input.readLong(); c9/ 'i
} M?:f^
input.close(); 8O}A/*1FJ
} mw%[qeLV
catch(IOException e){e.printStackTrace ();} bE%mgaOh
catch(Exception e){e.printStackTrace ();} UOOR0$4
} QvT-&|
cfQh
tleK(^
private void processErrorCode(int nErrorCode) Z{|.xgsY
{ (D+{0 /
System.err.println("Error Code : " + nErrorCode); #RZJ1uL
} 4jue_jsle
[M zc^I&
ADJ5ZD<Q
//停止文件下载 U_=wL
public void siteStop() Y+Q,4s
{ +A&IxsTq5=
bStop = true; *X=f
for(int i=0;i<nStartPos.length;i++) Dk.9&9mz
fileSplitterFetch.splitterStop(); j)SgB7Q
M,v@G$pW
bC,M&<N
} ]!S)O|_D[
} XiZ Zo
//负责部分文件的抓取 QYCNO#*
**FileSplitterFetch.java sD8xH
*/ VHY<(4@
package NetFox; xF:poi
;@ !d!&
:4L5@>b-
import java.io.*; ]FnrbQ|
import java.net.*; a[{QlD^D
|@n{tog+-
>c'_xa?^G
public class FileSplitterFetch extends Thread { E'kQ
>p+gx,N
\gW\Sa ^
String sURL; //File URL (nZ=9+j]d
long nStartPos; //File Snippet Start Position ez<wEtS
long nEndPos; //File Snippet End Position Exo`Z`m`U
int nThreadID; //Thread's ID Q; /!oA_
boolean bDownOver = false; //Downing is over g>oYEFFJ
boolean bStop = false; //Stop identical jKi*3-&
FileAccessI fileAccessI = null; //File Access interface eVK<%r=
^OcfM_4pN
\?ws0Ax
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _ JJ0pc9t
{ ;<GTtt#D
this.sURL = sURL; 71m-W#zyA
this.nStartPos = nStart; dfkTDG+
this.nEndPos = nEnd; gm8Tm$fY
nThreadID = id; u0H`%m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7JwWM2N?V
} q^+NhAMz
}Knq9cf
t>`LO
public void run() >^ 1S26
{ i&G`ah>
while(nStartPos < nEndPos && !bStop) \6 0WP-s
{ cj_?*
(tz]!Aa{s
M&T/vByTn_
try{ iOXP\:mPo
URL url = new URL(sURL); i/EiUH/~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >2{HH\
httpConnection.setRequestProperty("User-Agent","NetFox"); #i=^WN<V
String sProperty = "bytes="+nStartPos+"-"; H+&w7ER
httpConnection.setRequestProperty("RANGE",sProperty); `.-k%2?/
Utility.log(sProperty); a^/20UFq
U)1qsUDF
Llc|j&yHQ
InputStream input = httpConnection.getInputStream(); $i] M6<Vxn
//logResponseHead(httpConnection); $^aXVy5p
%+"AF+c3r
nhhJUN?8
byte[] b = new byte[1024]; H 6<@
int nRead; E1v<-UPbA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uM<+2S
{ }4MG114j
nStartPos += fileAccessI.write(b,0,nRead); zO]dQ$r\Z
//if(nThreadID == 1) HON[{Oq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5|t&qUV
} SO<K#HfE$?
kYa' ] m
$iJ #%&D
Utility.log("Thread " + nThreadID + " is over!"); :6iq{XV^
bDownOver = true; e(5R8ud
//nPos = fileAccessI.write (b,0,nRead); NdQ?3'WJ
} KePHn:c
catch(Exception e){e.printStackTrace ();} bFXCaD!{G
} nu-wQr
} tR/ JY;jn
V1qHl5"
V-u\TiL
//打印回应的头信息 .8~ x;P6
public void logResponseHead(HttpURLConnection con) J>v>6OC6i
{ m&8_i`%<
for(int i=1;;i++) 2yc\A3ft#
{ P=z':4,M}
String header=con.getHeaderFieldKey(i); svgi!=
if(header!=null) 7w({ GZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <#`L&w.
Utility.log(header+" : "+con.getHeaderField(header)); _<Tz1>j=
else $OuA<-
break; a$A S?`L
} -fn~y1
} c+VUk*c3
H^0KNMf(
l6O(+*6Us
public void splitterStop() r|8..Ll
{ =!aV?kNS8
bStop = true; y.OUn'^d4
} Rk^&ras_
W=+ag<@
LdV_7)
} >ZWm0nTr
nAOId90wue
6A<aelE*i
/* .v'8G)6g
**FileAccess.java *2Kte'+q
*//文件访问(定位，写) 4BX*-t
package NetFox; jkd8M;Jw
import java.io.*; *{Vyt5
4}`MV.
,;;~dfHm
public class FileAccessI implements Serializable{ 2t%)d9r32
qm_\#r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +{&g|V
RandomAccessFile oSavedFile; ZO}*^
long nPos; ?Eed#pb_
J2-xnUa]7
6$Y1[
public FileAccessI() throws IOException /on p<u
{ ]|oqJ2P
this("",0); mvnK)R_
} *niQ*A
gxiJ`.D=
e3.TGv7=
public FileAccessI(String sName,long nPos) throws IOException G(L*8U<UG
{ mDhU wZH
oSavedFile = new RandomAccessFile(sName,"rw"); 1Pbp=R/7ar
this.nPos = nPos; QLn5:&
oSavedFile.seek(nPos); - >2ej4C
} =0A{z#6
3!I8J:GZ:
4)?c[aC4P
public synchronized int write(byte[] b,int nStart,int nLen) F+X3CB,f
{ gS!M7xy
int n = -1; iJcl0)|
try{ Eyuc~[
oSavedFile.write(b,nStart,nLen); /*[a>B4-q
n = nLen; p"ZPv~("V
} DwI)?a_+
catch(IOException e) `7NgQ*g.d/
{ 0kDT:3
e.printStackTrace (); @{j-B IRZ0
} L^22,B 0
1i{B47|
HwOw.K<
return n; TYp{nWwi
} *J6qL! ["
0pu'K)Rb
<1ai0]
} "5@Y\L
SU*P@?:/}
8`*(lKiL
/* P9c1NX\-
**SiteInfoBean.java /(Y\ <
*/ T_r[#j
package NetFox; CnO$xE|{
Dq\#:NnKvx
s4w<X}O_
public class SiteInfoBean { SN+&'?$WD
v5&WW?IBQ
`toSU>:
private String sSiteURL; //Site's URL [QeKT8
private String sFilePath; //Saved File's Path lp4sO#>`
private String sFileName; //Saved File's Name }(gXlF
private int nSplitter; //Count of Splited Downloading File !\p-|51
&%^[2^H8"
p/@z4TCNX
public SiteInfoBean() h1,J<B@
{//nSplitter的缺省值为5 sH6srwI
//default value of nSplitter is 5 _,vJ0{*
this("","","",5); E]Kd`&^}
} =MMWcK&
tr):n@
fE7Kv_N-%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rsrv1A=t?
{ ${`\In_?O
sSiteURL= sURL; (RGl, x:
sFilePath = sPath; wjpkh~qo
sFileName = sName; H.'_NCF&;L
this.nSplitter = nSpiltter; y![h
594$X@!v
6Bs_" P[
} >4bOM@[]
dBCg$Rud&
2f F)I&
public String getSSiteURL() O>H4hp
{ J\#6U|a""u
return sSiteURL; UT"L5{c
} :s*&_y
9'O<d/xj/
U edh4qa
public void setSSiteURL(String value) +BmA4/P$
{ ?zxKk(J
sSiteURL = value; "x&H*"
} NeUpl./b
`Q}.9s_ri
URY%+u
public String getSFilePath() jt;68SA P
{ B7va#'ne4{
return sFilePath; yU&A[DZQ
} &9IMZAo
3)I v8mA
iQS?LksQX
public void setSFilePath(String value) rXvvJIbi
{ foaNB=,
sFilePath = value; [96|xe\s
} @~/LsYA:
(eG#JVsm9
/\h&t6B1
public String getSFileName() X2Y-TET
{ X=_N7!
return sFileName; qDOx5.d
} Pqx=j_st
^P(HX
Ch^Al2)=
public void setSFileName(String value) F71.%p7C8"
{ r!#NFek}
sFileName = value; zLC\Rc4
} M {_`X
m3K8hL/
f`P%aX'cBQ
public int getNSplitter() o=4d2V%m
{ h,0mJj-ma
return nSplitter; KGzBK:
} $v$~.
"VB-=. A
-.i1l/FzP
public void setNSplitter(int nCount) 315Rk!{AJ
{ |Zncr9b
nSplitter = nCount; cPkN)+K
} ZOyq{w!2
} }=az6cLE2
2U)H2%
i{ eDV
/* ?UQE;0 B
**Utility.java ?:~Y%4;
*/ \HV%579
package NetFox; /DJyNf*
X#Ajt/XQ
83Bp_K2\
public class Utility { e:6R+8s2
] +LleS5
ie=tM'fb
public Utility() 0r.*7aXu
{ $@7S+'Q3
9^c\$"2B
q_ykB8Ensa
} MX xRM~
/F5g@ X&
//线程睡眠 YJ_LD6PL9
public static void sleep(int nSecond) P}KyT?X:
{ #xNLr
try{ ~NMal]Fwx
Thread.sleep(nSecond); BOoLs(p
} r}+U1l3#2
catch(Exception e) ix=HLF-0zC
{ ^$4d'
e.printStackTrace (); 3<AZ,gF1
} %mAgE\y25
} ,9`sC8w|
"nf.kj:>
//日志 {]n5h#c 5*
public static void log(String sMsg) FQ*4?D,A
{ 0-oR { {
System.err.println(sMsg); wyMj^+ 2m
} H$9--p
X@*$3z#Z
"~jt0pp
public static void log(int sMsg) mA|!IhM
{ c8v+eyn
System.err.println(sMsg); &~29%Ns
} sZ/~pk
} /8VM.fr$
w*Vf{[a'
R+ lwOVX
/* ]j(2FM)#
**TestMethod.java (f,D$mX
*/ t|jX%s=
package NetFox; q+>J'UGb
Vv~rgNh
6.kX~$K
public class TestMethod { "2o,XF
7SE\(K=<%
Jtnuo]{R
public TestMethod() T^x7w+
{ ///xx/weblogic60b2_win.exe ^a4y+!
try{ XO~xbG7>gZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,F`:4=H%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kz\ D-b
SiteFileFetch fileFetch = new SiteFileFetch(bean); AdxCP\S&
fileFetch.start(); ?vuM'UH-
} `c ~Va/Yi
catch(Exception e){e.printStackTrace ();} 3<LG~HWST
uvz}qH@j/Q
7d*SZmD
} dPwe.:
QkBT,c
\Q7Nz2X
public static void main(String[] args) `X'-4/Y
{ =G2D4>q
new TestMethod(); 4vq,W_n.hQ
} OiH tobM
} PXof-W
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