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)); VCSHq&p8
} i ?&t@"'
for(int i=0;i<nEndPos.length-1;i++) twv|,kM
{ :hJHjh
nEndPos = nStartPos[i+1]; n+QUT
} Ebw1 %W KC
nEndPos[nEndPos.length-1] = nFileLength; cKJf0S:cx-
} cXU8}>qY7
} @<=xfs
Uy2NZ%rnt
"(zvI>A
//启动子线程 )h6hN"#V5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gHdNqOy c
for(int i=0;i<nStartPos.length;i++) UCG8=+t5T
{ e/Wrm^]y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ydm0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6i|5`ZO
nStartPos,nEndPos,i); x)N$.7'9OJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7|%|w
fileSplitterFetch.start(); i8iv{e2
} _1Iy/T@1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), " !F)K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \UA\0p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }(k#,&Fv`
nEndPos = " + nFileLength); TUHm.!+a
// fileSplitterFetch[nPos.length-1].start(); B~+3<#B
+Z> Y//
=r"-Pm{
//等待子线程结束 &|yQwNA*a"
//int count = 0; ~QgyhJM_h=
//是否结束while循环 %IrR+f+H
boolean breakWhile = false; ,I6jfXI4
%J(y2 }
.1n=&d|
while(!bStop) 'D`O4TsP>
{ 8XJg
write_nPos(); ).U\,@[A{
Utility.sleep(500); ZByxC*Cz
breakWhile = true; Geyy!sr``
B7PkCS&X
\|e>(h!l;
for(int i=0;i<nStartPos.length;i++) `_%UK=m
{ _gU:!:}
if(!fileSplitterFetch.bDownOver) t/55tL
{ !%MI9Ok
breakWhile = false; V`P8oIOh]
break; KaVNRS
} DJ_[{WAV
} wcr3ugvT
if(breakWhile) b-?wJSf|
break; eS#kDa/ %
$HgBzZ7A2
x}\x3U
//count++; O[}{$NXw
//if(count>4) {1?94rz
// siteStop(); U*sjv6*T
} LGnb"ZN
)/HbmtXqI
KLb"_1z
System.err.println("文件下载结束！"); [|iWLPO1&k
} +85#`{ D
catch(Exception e){e.printStackTrace ();} Nq]8p =e
} 5k:SD7^b
CD^C}MB
YcQ$nZAU
//获得文件长度 I0iTa99K
public long getFileSize() LR:PSgy
{ {!RDb'Zp
int nFileLength = -1; J?6.yL;
try{ 7Qdf#DG
URL url = new URL(siteInfoBean.getSSiteURL()); U ?iw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %MG{KG=&o
httpConnection.setRequestProperty("User-Agent","NetFox"); E_q/*}]pE
L hp
jej.!f:H
int responseCode=httpConnection.getResponseCode(); ~[8n+p+&X
if(responseCode>=400) rR Kbs@1M
{ q+iG:B/Z
processErrorCode(responseCode); %G0J]QY{(x
return -2; //-2 represent access is error 4X-"yQ<U
} CdBpz/
bG0 |+k3O
_V2^0CZ
String sHeader; Eep~3U
yqH
m:}PVJ-"
for(int i=1;;i++) LTZ8Eu
{ vYFtw L`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |>^5G@e
//Utility.log(in.readLine()); H1GmC`\<[:
sHeader=httpConnection.getHeaderFieldKey(i); [T |P|\M
if(sHeader!=null) N5PW]
{ -L-#-dK'
if(sHeader.equals("Content-Length")) 2[Ofa(mkkp
{ sKy3('5;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <OH{7>V
break; WCTmf8f
} e{Q;,jsh
} ai7R@~O:_k
else "D\>oFu
break; BGd# \2
} Bd'X~Vj<
} ?"F9~vx&G
catch(IOException e){e.printStackTrace ();} ol0i^d*9F
catch(Exception e){e.printStackTrace ();} ^ps6\>=0cW
&Fiesi!tET
W [*Go
Utility.log(nFileLength); Ln'y 3~@
,.kJF4s&
U[0x\~[$K
return nFileLength; zif&;)wV/
} c"O4=[N: ;
[psZc'q
dhX$b!DA
//保存下载信息（文件指针位置） Sj ly]
private void write_nPos() [vGkr" =
{ O~Jm<
try{ u^O!5 'D%
output = new DataOutputStream(new FileOutputStream(tmpFile)); &4O2uEW0
output.writeInt(nStartPos.length); YpOcLxFL
for(int i=0;i<nStartPos.length;i++) hW!2C6
{ r>e1IG
// output.writeLong(nPos); $7QGi|W*k
output.writeLong(fileSplitterFetch.nStartPos); l k sNy
output.writeLong(fileSplitterFetch.nEndPos); lfAiW;giJ
} TU6(Q,Yi|
output.close(); mtg=v@~
} $@D*/@
catch(IOException e){e.printStackTrace ();} wBWqibY|
catch(Exception e){e.printStackTrace ();} pCf9"LLer
} "ejsz&n
m#$$xG
?8w5tfN6t
//读取保存的下载信息（文件指针位置） `h|Y0x
private void read_nPos() cP",szcY
{ Dm@h'*
try{ Z0/$XS9|h;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |KR8=-!7
int nCount = input.readInt(); lak,lDt]
nStartPos = new long[nCount]; %[4u #G`
nEndPos = new long[nCount]; >akC
for(int i=0;i<nStartPos.length;i++) EI9;J-c
{ eZoAy[
nStartPos = input.readLong(); <NEz{1Z
nEndPos = input.readLong(); 85f:!p
} LOgFi%!6:
input.close(); !kG|BJ$j
} naro
catch(IOException e){e.printStackTrace ();} v.&c1hKHb
catch(Exception e){e.printStackTrace ();} dB)-qL8,2
} ?I8r2M]
uHsLlfTn
?y]R /?
private void processErrorCode(int nErrorCode) i[?VF\Y(
{ nC%<BatQ
System.err.println("Error Code : " + nErrorCode); ]v/pMg#-
} r$1b=m,0d
,#czx3?4
=r)LG,w212
//停止文件下载 y!dw{Lz
public void siteStop() 48Jt5Jz_
{ l^XOW- ;u
bStop = true; No8-Hm
for(int i=0;i<nStartPos.length;i++) d A'0'M
fileSplitterFetch.splitterStop(); %)72glB
3-=AmRxW't
^AShy`o^X
} %Z+**>1J
} 1:iB1TclP
//负责部分文件的抓取 *8J0yv
**FileSplitterFetch.java id588Y78
*/ >=d 5Scix
package NetFox; !PA><F
UT5xUv5'
K_AdMXF9
import java.io.*; mrq,kwM
import java.net.*; _s+G02/q1
OkAgO3>Y/
v8WT?%
public class FileSplitterFetch extends Thread { 2cO6'?b
(&1.!R[X
]bAVOKm-
String sURL; //File URL hH9~.4+*`g
long nStartPos; //File Snippet Start Position eZ$M#I=o
long nEndPos; //File Snippet End Position Sgr. V)
int nThreadID; //Thread's ID `rXb:P7m{j
boolean bDownOver = false; //Downing is over t 9t '9
boolean bStop = false; //Stop identical #1C]ZV] B
FileAccessI fileAccessI = null; //File Access interface :.tL~% q
Qcks:|5
Y]_$+Si:NK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1{5t.
{ )"?eug}D
this.sURL = sURL; aM xd"cTzx
this.nStartPos = nStart; ?K;l 5$?%
this.nEndPos = nEnd; jU kxA7 }}
nThreadID = id; Yg?BcY\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tUuARo7#
} Y]*&\Ex"\
j/_&]6!
C0K: ffv;<
public void run() Fg 8lX9L
{ ^Vhl@
while(nStartPos < nEndPos && !bStop) CPL,QVO9
{ e/_QS}OA
pGfGGY>i%
s_}6#;
try{ ZPY&q&R
URL url = new URL(sURL); :5['V#(o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6" <(M@
httpConnection.setRequestProperty("User-Agent","NetFox"); K@JaN/OM
String sProperty = "bytes="+nStartPos+"-"; ahIDKvJ4
httpConnection.setRequestProperty("RANGE",sProperty); ij|>hQC5i
Utility.log(sProperty); w[D]\>QHa
p!~1~q6
D)pTE?@W'
InputStream input = httpConnection.getInputStream(); >_xuXEslUz
//logResponseHead(httpConnection); vBJxhK-
dC8}Ttc}
*`|xa@1v`
byte[] b = new byte[1024]; 3u/AqL
int nRead; !yVY[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dA (n,@{
{ z;dRzwL
nStartPos += fileAccessI.write(b,0,nRead); tHo|8c~[
//if(nThreadID == 1) K,JK9)T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \EU^`o+
} \@yJbhk
{;E6jw@
A^p{Cq@E
Utility.log("Thread " + nThreadID + " is over!"); 9gdK&/ulR
bDownOver = true; (X Oz0.W
//nPos = fileAccessI.write (b,0,nRead); UlXxG|
} >d=pl}-kOQ
catch(Exception e){e.printStackTrace ();} Ue60Mf
} ;2\6U;
} W8$0y2
122s7A
dCS f$5
//打印回应的头信息 ]jm:VF]4
public void logResponseHead(HttpURLConnection con) 5y 5Dn!`
{ $|@vmv0
for(int i=1;;i++) m(?{#aaq
{ b1cVAfUP
String header=con.getHeaderFieldKey(i); <ShA_+Nd
if(header!=null) |0oaEd^*}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Hj;i/zD
Utility.log(header+" : "+con.getHeaderField(header)); R|'W#"{@
else Y)]C.V,~
break; rX /'
} +&S6se4
} x~R,rb
I#M>b:"te
Dw7Xy}I/
public void splitterStop() \>pm (gF
{ QK#wsw
bStop = true; ^r.CUhx)
} L'S,=NYXY
)qw;KG0F
})P!7t
} )gSqO{Z
DpvHIE:W
d"miPR
/* %7}j|eS)G
**FileAccess.java 9]w?mHslE
*//文件访问(定位，写) "f_qG2A{
package NetFox; K)wWqC.
import java.io.*; TEY~E*=}$
hmd3W`8D
S4 Uu/EX6S
public class FileAccessI implements Serializable{ Dol{y=(3e
DBB&6~;?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fglfnx0{
RandomAccessFile oSavedFile; A]5];c
long nPos; YS){N=g&'
Y1I)w^}:
A]'jsv!+
public FileAccessI() throws IOException ,!@MLn
{ &Q;sbI}
this("",0); $C5*@`GM$
} 2vLun
72"H#dy%U
;h+~xxu=X
public FileAccessI(String sName,long nPos) throws IOException [RN]?,
{ 5|*`} ;/y
oSavedFile = new RandomAccessFile(sName,"rw"); N'9T*&o+
this.nPos = nPos; z8awND
oSavedFile.seek(nPos); ;*<R~HJt
} uOeal^uS
p> >H$t
tkcs6uy
public synchronized int write(byte[] b,int nStart,int nLen) oC49c~`8
{ znTi_S
int n = -1; 1<73uR&b%
try{ >8kXa.)84
oSavedFile.write(b,nStart,nLen); @WS77d~S
n = nLen; 86 e13MF
} ;J TY#)Bh
catch(IOException e) e9RYk:O
{ [V:~j1{3
e.printStackTrace (); Vi-Ph;6[
} <MkvlLu((o
Vez8~r3
N;'c4=M~(
return n; jK]1X8
} 2{63:f1c`'
0jlM~H
n.2:fk
} j\~,Gtn>Z
+71<B>L
qc @cdi
/* ./k7""4
**SiteInfoBean.java _8u TK%|
*/ 5kTs7zJ^
package NetFox; Y06^M?}
jBYvOy*$Q
15Mtlb
public class SiteInfoBean { hFv{?v
oH%[8!#
I{g.V|+x
private String sSiteURL; //Site's URL ~W8Xg)
private String sFilePath; //Saved File's Path !Z:XSF[T
private String sFileName; //Saved File's Name oC>J{z
private int nSplitter; //Count of Splited Downloading File Lo!hyQ)
zT78FliY6
}u O YF
public SiteInfoBean() vJ65F6=G
{//nSplitter的缺省值为5 I@ueeDY
//default value of nSplitter is 5 )8W! |
this("","","",5); h>\C2Q
} P\ke%Jdpw?
/ki-Tha
XlU\D}zS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "Esl I
{ WSH[*jMA
sSiteURL= sURL; FefroaJ:u
sFilePath = sPath; n>q!m@ }<
sFileName = sName; %T]^,y$n
this.nSplitter = nSpiltter; K9k!P8Rd
Q*>)W{H&)
n>y,{"J{
} 37zBX~
:,JaOn'
3Xu|hkK\e
public String getSSiteURL() 5N|LT8P}Z
{ -[-oz0`Sl{
return sSiteURL; yqq1a o
} ewk7:zS/?
JpfA+r
>[;@ [4}
public void setSSiteURL(String value) 5;0w({1l
{ -/JEKwc
sSiteURL = value; (^}t
} ?lsK?>uU
.u7}p#
)C8^'*!
public String getSFilePath() 34u[#O{2
{ cr!W5+r
return sFilePath; Jh EC
} iX+8!>Q
JKM(fX+
+ausm!~6
public void setSFilePath(String value) I </P_:4G
{ f $Agcy
sFilePath = value; "i;.>
} xO )c23Z)]
c]|vg=W
n;Oe-+oSC
public String getSFileName() 5Z!$?J4Rl
{ nd8<*ru$
return sFileName; )_jboaNzwI
} _:m70%i
A{zqr^/h
N3L$"g5^
public void setSFileName(String value) h(/? 81:
{ PF`uwx@zH
sFileName = value; ZR}v_]l^
} eA!Z7 '
.A< HM}
Og7yT{h_
public int getNSplitter() AhF@
{ YP02/*'
return nSplitter; gt}Atr6>_
} DA "V)
<=7nTcO~
zVS{X=u
public void setNSplitter(int nCount) g9pKoi|\E
{ <\^o
nSplitter = nCount; crIF5^3Yby
} JU>~[yAP
} _s^tL2Pc
{S=<(A@
uQO5GDuK>
/* 5qnei\~
**Utility.java }gv'r ";
*/ 9!n:hhJM
package NetFox; l7VO8p]y[R
\|Af26
.z,-ThTH@\
public class Utility { ElW\;C:K*
MeBTc&S<
Z2]0brV
public Utility() mKe6rEUs|
{ =T[P
arm_SyL0
K]m#~J3d>
} s=jmvvs_V}
[}4zqY{
//线程睡眠 #g6_)B=S
public static void sleep(int nSecond) H2jypVs$2
{ X <xM '
try{ %0-oZL
Thread.sleep(nSecond); yf:0u_&]
} u<:uL
catch(Exception e) ^s6~*n<fH
{ ([q>.[WbH]
e.printStackTrace (); V4Rs
} m-O*t$6
} j_rO_m<8
QIkFX.^
//日志 gV@xu)l
public static void log(String sMsg) ^`yhN
{ @sn:%/x_
System.err.println(sMsg); LOkgeJuWv
} }SSg>.48w
~},H+A!?
6n2RTH
public static void log(int sMsg) R9A:"sJ
{ Ms6;iW9
System.err.println(sMsg); VjWJx^ZL#
} i<Ms2^
} q<E7qY+
c/K#W$ l
HHx:s2G
/* z#Jw?K_
**TestMethod.java l5w^rj
*/ tQzbYzGb7
package NetFox; oqwW
!6|_`l>G,
w~B1TfqNo
public class TestMethod { K;"H$0!9
8 siP
[6VM4l"
public TestMethod() LE}`rW3
{ ///xx/weblogic60b2_win.exe ??nT[bhQ
try{ EN`JzLjP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 28^/By:J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #6@hVR.
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0t!ZMH
fileFetch.start(); 9q?knMt
} 5]*lH t
catch(Exception e){e.printStackTrace ();} esSj 3E
mfZbo#KS#v
|iJz[%
} (Yj6|`
Q)aoc.f!v
;0WAfu}#H
public static void main(String[] args) <T7@,_T
{ !=21K0~t#
new TestMethod(); ^r}Uu~A>
} Ut~YvWc9
} -!+i ^r
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