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)); 5'<J@3B
} I]@QhCm0
for(int i=0;i<nEndPos.length-1;i++) "lVbla4b
{ .u3;
nEndPos = nStartPos[i+1]; po! [Nd&"
} uVth&4dh9
nEndPos[nEndPos.length-1] = nFileLength; QbJE+m5
} }j)][{i*x
} R+*-i+]Q#7
R@df~
uv|RpIve:
//启动子线程 sB@9L L]&|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nf5zQ@o_y
for(int i=0;i<nStartPos.length;i++) i}L*PCP
{ $x/VO\Z{-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A3Xfu$[u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <B Vx%
nStartPos,nEndPos,i); Hg~8Td**
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >qy$W4
fileSplitterFetch.start(); j'uzjs[
} qV#,]mX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cy64xR BB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qef5eih
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M7fPaJKL
nEndPos = " + nFileLength); IKrojK8-?
// fileSplitterFetch[nPos.length-1].start(); Y1wH_!%b
%ONU0xtqk
J4]tT pu"K
//等待子线程结束 !59,<N1Iu
//int count = 0; Q<Q?#v7NX
//是否结束while循环 0 wjL=]X1e
boolean breakWhile = false; eemC;JV%
5oe{i/#di
F2>W{-H+
while(!bStop) .~a.mT
{ < ZG!w^
write_nPos(); \nUJ)w
Utility.sleep(500); >:bXw#w]
breakWhile = true; TVZf@U
+<T361eyY
<CcSChCg
for(int i=0;i<nStartPos.length;i++) s7(1|}jh
{ v=_Ds<6n
if(!fileSplitterFetch.bDownOver) en"\2+{Cg
{ }U^iVq*
breakWhile = false; Xf;_r+;
break; mwMcAUD]2
} ,`ba?O?*G
} ?>1wZ
if(breakWhile) 6T5\zInd
break; #z61I"kU
2U`!0~pod
^v&"{2
//count++; Nh01NY;
//if(count>4) rA|&G'
// siteStop(); '};mBW4z
} \Ez&?yb/
'=+gweM
M4n0GWHLy
System.err.println("文件下载结束！"); Cb6K!5[q]
} U]&/F{3 im
catch(Exception e){e.printStackTrace ();} Mn 8| Knh
} 0Q~\1D 9g
Gs>4/
!<<wI'8
//获得文件长度 Jsa;pG=3&
public long getFileSize() \bies1TBB^
{ 3T /_#=9TV
int nFileLength = -1; ,T-xuNYC
try{ 6st^-L
URL url = new URL(siteInfoBean.getSSiteURL()); !y862oKD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t9.| i H
httpConnection.setRequestProperty("User-Agent","NetFox"); (+nnX7V?I
w5vzj%6i
DH"_.j
int responseCode=httpConnection.getResponseCode(); 3fUiYI|&7
if(responseCode>=400) ~Zw37C9J
{ y\n#`*5k
processErrorCode(responseCode); "[sr0'g:
return -2; //-2 represent access is error g^{a;=
} )m Ii.
l\TL=8u2c
Q yhu=_&
String sHeader; T5-Yqz
pI1g<pe
!ZM*)6^
for(int i=1;;i++) y~z&8XrH
{ g77:92
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .dn#TtQv
//Utility.log(in.readLine()); [M#(su0fv
sHeader=httpConnection.getHeaderFieldKey(i); )=!|^M
if(sHeader!=null) y,6KU$G
{ >x]ir
if(sHeader.equals("Content-Length")) ~"Su2{"8B
{ L/)eNZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N+vsQ!Qz
break; z2jS(N?J1
} xxG>Leml
} L=5Y^f'aU
else xg4wtfAbS
break; )Wk&c8|y
} hbSKlb0d
} Of-8n-
catch(IOException e){e.printStackTrace ();} EgRuB@lw76
catch(Exception e){e.printStackTrace ();} h(i_'P?
8g?2( MT;
s~A:*2\
Utility.log(nFileLength); F5+!Gb En
+1K=]#a
!FQS9SoO9
return nFileLength; \1eWI
} dFZh1*1
z"*3p8N
_y:aPn
//保存下载信息（文件指针位置） \okvL2:!
private void write_nPos() Z ?ATWCa
{ IH"_6s#$&
try{ uM[[skc
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9Qq%Fw_
output.writeInt(nStartPos.length); Icx)+Mq
for(int i=0;i<nStartPos.length;i++) ;,Os3
{ "2:#bXM-
// output.writeLong(nPos); q8&^E.K
output.writeLong(fileSplitterFetch.nStartPos); N_p^DP
output.writeLong(fileSplitterFetch.nEndPos); 8\bZ?n#dn
} Gb.}af#v
output.close(); ^Yo2R
} ")u)AQ
catch(IOException e){e.printStackTrace ();} u&'&E
catch(Exception e){e.printStackTrace ();} KcM+8W\
} a fB?js6
T^gi^{
Q) iN_|
//读取保存的下载信息（文件指针位置） GXR7Ug}k
private void read_nPos() \,G19o}`Es
{ '<h@h*R
try{ -AXMT3p=1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]_hXg*?
int nCount = input.readInt(); s5ILl wr
nStartPos = new long[nCount]; F~3 &@TWi
nEndPos = new long[nCount]; m@yx6[E#
for(int i=0;i<nStartPos.length;i++) {sUc2vR
{ 7 .xejz
nStartPos = input.readLong(); ,%KMi-w]q,
nEndPos = input.readLong(); YVO~0bX:
} ah!fQLMH
input.close(); /4 .]L~
} _<jccQ
catch(IOException e){e.printStackTrace ();} Mvk#$:8e
catch(Exception e){e.printStackTrace ();} %p};Di[V
} !^3j9<|@'
Y|<1|wGG
;_1>nXh
private void processErrorCode(int nErrorCode) [[Usrbf
{ c#pVN](?
System.err.println("Error Code : " + nErrorCode); gWy2E;"a
} ScC!?rTW~7
{\kDu#18Ld
xKoNo^FF
//停止文件下载 {6*{P!H
public void siteStop() Of{'A
{ w&}UgtEm
bStop = true; 7P DD
for(int i=0;i<nStartPos.length;i++) ^j'vM\^`ml
fileSplitterFetch.splitterStop(); ntF#x.1Pm
[~ |e:
gR{.0e
} q?oJ=]m"
} g%d&>y?1r
//负责部分文件的抓取 "Oy&6rrr
**FileSplitterFetch.java dYhLk2
*/ mWU*}-M
package NetFox; Q$2^m(?;
|)Sx"B)
tA9(N>[*
import java.io.*; +,}CuF
import java.net.*; >V3pYRA
2 Xc,c*r
i{2rQy+
public class FileSplitterFetch extends Thread { ++0xa%:
EB>rY
?T:$:IHw
String sURL; //File URL [>f4&yY
long nStartPos; //File Snippet Start Position @0rwvyE=+3
long nEndPos; //File Snippet End Position !O#NP!
int nThreadID; //Thread's ID 9rQpKq:# E
boolean bDownOver = false; //Downing is over [u`9R<>c"U
boolean bStop = false; //Stop identical FZtILlw
FileAccessI fileAccessI = null; //File Access interface cH$Sk
_:9-x;0H2
"zN]gz=OV>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )IZ~!N|-w
{ [es-&X07<
this.sURL = sURL; yO09NQ 5u
this.nStartPos = nStart; s)|l-I
this.nEndPos = nEnd; O:G-I$F|
nThreadID = id; !yX4#J(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;hp?wb
} ppM^&6x^
'^.}5be&
y'pX/5R0
public void run() #oD*H:%*
{ ^k}jPc6
while(nStartPos < nEndPos && !bStop) }[I|oV5*+&
{ ^<O:`c6_
& pS5_x
{!vz 6QDS
try{ Fu!sw]6xx
URL url = new URL(sURL); CI6qDh6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cX/["AM
httpConnection.setRequestProperty("User-Agent","NetFox"); Qws#v}xF
String sProperty = "bytes="+nStartPos+"-"; k`Ifd:V.y
httpConnection.setRequestProperty("RANGE",sProperty); G!IJ#|D:~
Utility.log(sProperty); (1b%);L7
R?[KK<sWWe
c{t(),nAA
InputStream input = httpConnection.getInputStream(); ~WG#Zci-
//logResponseHead(httpConnection); p![CH
Y+I`XeY
ssC5YtF7X
byte[] b = new byte[1024]; tmI2BBv
int nRead; ocT.2/~d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l~Sn`%PgA
{ sGD b<
nStartPos += fileAccessI.write(b,0,nRead); UZ+FV;<
//if(nThreadID == 1) Bx32pY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JMq00_
} f<0nj?
~8G<Nw4*\
L3-tD67oa
Utility.log("Thread " + nThreadID + " is over!"); o$DJL11E
bDownOver = true; oLp:Z=
//nPos = fileAccessI.write (b,0,nRead); X`k[ J6
} u)fmXoQ
catch(Exception e){e.printStackTrace ();} !]k$a
} K r&HT,>B
} i3} ^j?jA2
]gQ4qu5
5:H9B
//打印回应的头信息 ?pv}~>
public void logResponseHead(HttpURLConnection con) DHV#PLbN$
{ fw1g;;E
for(int i=1;;i++) L_YVe(dT
{ K}U}h>N
String header=con.getHeaderFieldKey(i); bh1WD_
if(header!=null) W@x UR-}51
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @"#W\m8
Utility.log(header+" : "+con.getHeaderField(header)); 6"W~%FSJX
else 43Yav+G(+
break; 'L2M W
} }$ Am;%?p
} :d<;h:^_
Dyj5a($9"{
\5_7!.
public void splitterStop() &@xixbg
{ U/oncC5
bStop = true; mu/O\'5
} ArUGa(;f
WoiK _Ud
Hs+VA$$*
} "oYyeT ,?
)[>b7K$f
8]N+V:
/* B{SzC=4f}
**FileAccess.java RYaf{i`
*//文件访问(定位，写) 8JUUK(&Z
package NetFox; V(Ps6jR"BS
import java.io.*; rQbL86+
t,.MtU>K@
n@xDFa
public class FileAccessI implements Serializable{ j#b?P=|l
:hG?} [-2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'Z+~G
RandomAccessFile oSavedFile; z2&SZ.mk
long nPos; +?~'K&@
u4=j!Zb8}
e1X*}OI
public FileAccessI() throws IOException z1ltc{~Z
{ }06
this("",0); M ,8r{[2
} H85HL-{
x(z[S$6Y\
~3.1. 'A
public FileAccessI(String sName,long nPos) throws IOException I#kK! m1Q
{ *Ri?mEv hF
oSavedFile = new RandomAccessFile(sName,"rw"); 0EYK3<k9!
this.nPos = nPos; S ;x;FU
oSavedFile.seek(nPos); dm&F1NkT
} 9LGJ-gL
0!rU,74I=
H'$g!Pg
public synchronized int write(byte[] b,int nStart,int nLen) XGEAcN
{ !p1OBS|
int n = -1; h@T}WZv
try{ 7{:| )
oSavedFile.write(b,nStart,nLen); RR><so%
n = nLen; J56+eC(
} B3'qmi<
catch(IOException e) uRQm.8b
{ u7&r'rZ1_!
e.printStackTrace (); U6"U^
} tgDmHxB]0
9/RbfV[)
SM5i3EcFYP
return n; UcDJ%vI
} [K[tL|EK
~<3qsA..
4em7PmT
} vfJ}t#%UH
pFGK-J
k'wF+>
/* S'HM|&
**SiteInfoBean.java O9]j$,i
*/ _$By c(.c
package NetFox; Wy,DA^\ef
"TKf"zc
zGu(y@o
public class SiteInfoBean { gqJ&Q t#f
%FQMB
%lV&QQa
private String sSiteURL; //Site's URL %L{H_;z
private String sFilePath; //Saved File's Path j_\sdH*r
private String sFileName; //Saved File's Name 'bkecC
private int nSplitter; //Count of Splited Downloading File {SW104nb&#
|,5b[Y"Dt
4-=>># P
public SiteInfoBean() \w^iSK-
{//nSplitter的缺省值为5 t-lWvxXe
//default value of nSplitter is 5 %$I\\qq>{
this("","","",5); 7CABM
} }3Pz{{B&+O
;'dw`)~jQ
X(1nAeQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s'ntf
{ T.!GEUQ
sSiteURL= sURL; N- ?U2V
sFilePath = sPath; 3`J?as@^8
sFileName = sName; hyL3fkMJ,
this.nSplitter = nSpiltter; n w @cAv
|v}"UW(y
,m!j2H}8
} R*E/E
H]Q Z4(
._=Pa)T
public String getSSiteURL() 6 EE7<&
{ [Zl
return sSiteURL; Et%s,zeA{2
} x';6
<[?oP[ j
9C$b^wHd
public void setSSiteURL(String value) OAR1u}
{ _+%-WFS|
sSiteURL = value; xg'z_W
} ME1lQ7E4B
"4H&wHhT!
3ZU`}
public String getSFilePath() Z~~{!C+G
{ +e%9P%[+
return sFilePath; Tm_AoZH
} xqO'FQO%
RERum
zVZZdG~8
public void setSFilePath(String value) hv}rA,Yd
{ #wNksh/J^
sFilePath = value; q*Yh_IT.I
} AASw^A3p
z*YkD"]B
AR]y p{NS
public String getSFileName() II)\rVP5
{ PLKp<kg
return sFileName; IBf&'/ 8\
} rv&(yA
S$+vRX7
,4jkTQ*@2
public void setSFileName(String value) wZh&w<l'
{ %(Nu"3|$K=
sFileName = value; ._~_OVU
} (X,Ua+{
za1MSR
vO%n~l=
public int getNSplitter() p8oOm>B96n
{ .rD@Q{e50
return nSplitter; jB:$+k|~.
} *&+e2itmp
5iz]3]}%
IBcCbNs!
public void setNSplitter(int nCount) ~{0:`)2FQ
{ a:Y6yg%1>
nSplitter = nCount; \kvd;T#t6
} rm;'/l8Y-E
} VThcG( NF
uo_Y"QiKEH
L|qQZ=
/* Tw)nFr8oF]
**Utility.java `Ff3H$_*
*/ KIC5U50J
package NetFox; ~_QZiuq&
UQaLhKv:
~urIA/
public class Utility { 2#kR1rJP
dd@^e)VZB
93XTumpV
public Utility() &vLz{
{ ,icgne1j
mFjX
,fpu@@2
} e ,/I}W
u&/q7EBfP
//线程睡眠 l{>fma]7
public static void sleep(int nSecond) Uy5IvG;O+
{ =zDU!< U
try{ @JZ I
Thread.sleep(nSecond); ?FVX &{{V
} w>p0ldi
catch(Exception e) @vss:'l
{ \6-x~%xK
e.printStackTrace (); -GD_xk
} AMG}'P:
} ^I~2t|}
|Up+Kc:z/n
//日志 3xxQL,FV
public static void log(String sMsg) pzbR.L}'D
{ 8V>j-C
System.err.println(sMsg); .mn`/4
} NKvBNf|D
dFS>uIT7X
+(x^5~QX
public static void log(int sMsg) !jN}n)FSq
{ <|cnQj*
System.err.println(sMsg); mM!'~{r[-
} jGl8y!aM
} U s86.@|
}&I\a
]>E*s3h
/* PUV)w\!&is
**TestMethod.java uMh[Ht^.
*/ V%8?f,
package NetFox; NZdjS9
J 05@SG':
a|SgGtBtT4
public class TestMethod { .+MJ' bW
<+o-{{E[
jl;_lcO
public TestMethod() rL3<r
{ ///xx/weblogic60b2_win.exe mEfI2P)#|
try{ /vll*}}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1 0lvhzU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5ppOG_
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'MRvH lCM
fileFetch.start(); $}_N379&
} G#gUd'=M
catch(Exception e){e.printStackTrace ();} f]`#BE)V
n0F.Um
FRd!UqMXY
} (+68s9XS7
C93BK)$}
Xf!@uS6<X
public static void main(String[] args) J(JsfU4
{ G3'>KMa.
new TestMethod(); ?YWfoH4mS
} ,(dg]7
} bO 2>ced
点击下载更多相关资料