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)); 91k-os(4]
} JbXi|OS/
for(int i=0;i<nEndPos.length-1;i++) K>-01AGHL
{ /d$kz&aIV
nEndPos = nStartPos[i+1]; A[:(#iR5-E
} \GGyz{i
nEndPos[nEndPos.length-1] = nFileLength; iU#"G" &
} SkU9iW(k
} b$`/f:_
DYgz;Y/%l
r[2*K 9
//启动子线程 T?7++mcA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U.N&~S
for(int i=0;i<nStartPos.length;i++) # `@jVX0
{ !0v3Lu~j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ao7pvU6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MK!Aq^Jz
nStartPos,nEndPos,i); iD>H{1 h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <J.q[fd1*
fileSplitterFetch.start(); =RofC9,
} 0XA0b1VX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1_M}Dc+J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iY5V4Gbo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mh}vr%0;)
nEndPos = " + nFileLength); nrbP3sf*
// fileSplitterFetch[nPos.length-1].start(); o ethO
[|(=15;
oZi{v]4
//等待子线程结束 Qp>Z&LvC5
//int count = 0; lLU8eHf\
//是否结束while循环 OLqynY
boolean breakWhile = false; lZ) qV!<
KD--w(4
EWOa2^%}Z\
while(!bStop) nt%p@e!,
{ d\r-)VWSr"
write_nPos(); x1}Ono3"T
Utility.sleep(500); A!R'/m'VG
breakWhile = true; kX+98?h-C
p+b$jKWQ
SEH[6W3
for(int i=0;i<nStartPos.length;i++) Sar1NkD#
{ Xx\,<8Xn
if(!fileSplitterFetch.bDownOver) s3VD6xi7
{ 8fPTxvXqL
breakWhile = false; 2W#^^4^+
break; 4b6)+*[O
} [ B*r{
} {$v^2K'C
if(breakWhile) )RQQhB
break; ]kF1~kXBe
UKPr[
dEW= V"W
//count++; kU.@HJ[@j
//if(count>4) PX`xr1o
// siteStop(); {uJ"%
} z";(0%
vJS}_j]_@
A8Km8"
System.err.println("文件下载结束！"); XWq"_$&LF
} ?TI]0)
catch(Exception e){e.printStackTrace ();} {CNJlr@z
} .i^@v<+
9~jS_Y)"
^66OzT8A
//获得文件长度 DfVJ~,x~
public long getFileSize() M}q;\}
{ a2/Mf
int nFileLength = -1; Z'Pe%}3
try{ 0G2Y_A&e**
URL url = new URL(siteInfoBean.getSSiteURL()); J6"GHbsO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M0OIcMTv
httpConnection.setRequestProperty("User-Agent","NetFox"); B+Ft >
q- 0q:
16 \)C/*
int responseCode=httpConnection.getResponseCode(); *xY3F8
if(responseCode>=400) 1kR. .p<"
{ B]Ec
processErrorCode(responseCode); M^>l>?#rl
return -2; //-2 represent access is error t*H|*L#YR
} WWo"De@
nHRk2l|
4^ U%` 1
String sHeader; ]lqZ9rO
(hg6<`
xtKU;+#
for(int i=1;;i++) #kA?*i[T
{ }[h]z7e2S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lP*=4Jh
//Utility.log(in.readLine()); .D\oKhV(
sHeader=httpConnection.getHeaderFieldKey(i); B692Mn
if(sHeader!=null) )jg*u}u 0
{ ^:}C,lIrG
if(sHeader.equals("Content-Length")) FK94CI
{ NffKK:HvBB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); + #E?)
break; #y[omla8
} B& R?{y*
} -Fu,oEj{*
else xXa4t4gR
break; _\Z'Yl
} +v:]#1
} dNF_T?E\
catch(IOException e){e.printStackTrace ();} 8{ =ha
catch(Exception e){e.printStackTrace ();} `h'=F(v(}
+"bi]^\z
8oXp8CC
Utility.log(nFileLength); ( ^@i(XQ
DHx&%]r;D
b-#lKWso
return nFileLength; 1 A0BM
} Y4swMN8Bq
)pT5"{
@TX@78fWz=
//保存下载信息（文件指针位置） y'I m/{9U
private void write_nPos() 96QY0
{ hsS&|7Pt
try{ tcsb]/my
output = new DataOutputStream(new FileOutputStream(tmpFile)); @G=7A;-pv0
output.writeInt(nStartPos.length); G$&jP:2q
for(int i=0;i<nStartPos.length;i++) }1~9i'o%Z
{ js"5{w&
// output.writeLong(nPos); b=pk;'-
output.writeLong(fileSplitterFetch.nStartPos); zwJ&K;"y(
output.writeLong(fileSplitterFetch.nEndPos); >~Tn%u<
} #\n*Qg4p
output.close(); /IJy'@B
} *AGf'+j*z
catch(IOException e){e.printStackTrace ();} 92A9gY
catch(Exception e){e.printStackTrace ();} LP|YW*i=IQ
} t8h*SHD9
\4G9YK-N>
II.:k.D`
//读取保存的下载信息（文件指针位置） q oi21mCn
private void read_nPos() t&q~ya/C
{ {z0iWY2Xw
try{ aGi`(|shW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?Z?(ky!
int nCount = input.readInt(); { AYW C6Y
nStartPos = new long[nCount]; -)')PV_+
nEndPos = new long[nCount]; xsJXf @
for(int i=0;i<nStartPos.length;i++) UdM2!f
{ R2-F@_
nStartPos = input.readLong(); {j]cL!Od
nEndPos = input.readLong(); 5 m-/N?c
} 4OgH+<G
input.close(); ]YFjz/f
} 4W*o:Y!
catch(IOException e){e.printStackTrace ();} ,h'Q
catch(Exception e){e.printStackTrace ();} :adz~L$
} WlvT&W
l/zv >
UWV%y P
private void processErrorCode(int nErrorCode) ~//E'V-
{ |/n7(!7$[v
System.err.println("Error Code : " + nErrorCode); \X%FM"r
} YARL/V
ov,s]g83
s_fe4K
//停止文件下载 0LL0\ly]
public void siteStop() ~B"HI+:\L
{ xp95KxHHo
bStop = true; 5= &2=
for(int i=0;i<nStartPos.length;i++) 8_HBcZWs
fileSplitterFetch.splitterStop(); i)X~L4gn
GEf=A.WAfw
X coPkW
} _1G/qHf^S
} (E00T`@t0i
//负责部分文件的抓取 fv8x7l7
**FileSplitterFetch.java H(76sE
*/ aaY AS"/:
package NetFox; c]#}#RJ`\
W& 0R/y7
-sJD:G,%
import java.io.*; fTy:Re
import java.net.*; B?8*-0a'[
Bx|W#:3e
#n|5ng|CJ
public class FileSplitterFetch extends Thread { ANw1P{9*
[=jZP,b&),
ky[Cx!81C
String sURL; //File URL 0/f|ZH ~!
long nStartPos; //File Snippet Start Position 2ak]&ll+h
long nEndPos; //File Snippet End Position zMP6hn
int nThreadID; //Thread's ID T=42]h
boolean bDownOver = false; //Downing is over IL.bwtpQD
boolean bStop = false; //Stop identical dyn)KDS
FileAccessI fileAccessI = null; //File Access interface Y(7&3+'K
`0]N#G T
Ep./->fOA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }9\6!GY0
{ z3S"1L7
this.sURL = sURL; @Drl5C}+
this.nStartPos = nStart; |Ol29C$@|
this.nEndPos = nEnd; ]aF;
nThreadID = id; d"-I^|[OM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8h=m()Eu
} ]m 3cm
Y2l;NSWU
klQmo30i
public void run() VZcW 3/Y
{ v4|TQ8!wR
while(nStartPos < nEndPos && !bStop) [nVBnB
{ TX$dxHSPK
w#A\(z%;x
`x _(EZ
try{ y'^U4# (
URL url = new URL(sURL); |T"vF`Kr(>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c8mh#Tbl
httpConnection.setRequestProperty("User-Agent","NetFox"); c$ib-
String sProperty = "bytes="+nStartPos+"-"; GP4!t~"1
httpConnection.setRequestProperty("RANGE",sProperty); C=&n1/
Utility.log(sProperty); Ve"(}z
7$%G3Q|)L
kI(3Pf].
InputStream input = httpConnection.getInputStream(); T<Xw[PEnP
//logResponseHead(httpConnection); oCkG
y(g]:#
H:hM(m0?q
byte[] b = new byte[1024]; l+2NA4s
int nRead; V0>[bzI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 64U|]gd$
{ n;:.UGl9.
nStartPos += fileAccessI.write(b,0,nRead); y{3+Un
//if(nThreadID == 1) ldp9+7n~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p({@t=L3g
} 1QA/ !2E
WynTU?
&S+*1<|`K
Utility.log("Thread " + nThreadID + " is over!"); pm=O.)g4`
bDownOver = true; XZ.D<T"
//nPos = fileAccessI.write (b,0,nRead); "Ua-7Q&A
} &D[M<7T
catch(Exception e){e.printStackTrace ();} 25`W"x_
} GFPrK9T
} u{=h%d/
;0kAm Vy
B=]L%~xL$
//打印回应的头信息 Ih5Y7<8b~
public void logResponseHead(HttpURLConnection con) S[9b I&C
{ b*S,8vE]
for(int i=1;;i++) qk'&:A
{ ZMMx)}hS
String header=con.getHeaderFieldKey(i); j}Svb1A
if(header!=null) Xlug{ Uh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PtUS7[]
Utility.log(header+" : "+con.getHeaderField(header)); t1iz5%`p}
else 1&e8vVN
break; 8g{Mv#b%
} q7aqbkwz}
} "wV
j8e=],sQ
-tWxBGSa@
public void splitterStop() |b='DJz2
{ rusM]Z
bStop = true; "&D0Sd@[?
} Z-CA9&4Uh
*wqR.n?
!X"nN9k
} [?<v|k
g8Y)90 G
0hkYexX73
/* =HMCNl
**FileAccess.java 3VMaD@nYa
*//文件访问(定位，写) 1=+S'_j
package NetFox; D?Ol)aj?
import java.io.*; 8TH;6-RT
{s*1QBM$\Z
QrSO%Rm1*
public class FileAccessI implements Serializable{ K(MZ!>{
h^IizrqU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2HE<WI^#h
RandomAccessFile oSavedFile; [=.iJ5,{2
long nPos; FR50y+h^$
\N?lG q
*hFJI9G
public FileAccessI() throws IOException j";L{
{ uW}M1kq?+l
this("",0); fK@UlMC]7
} ^N ;TCn
kp?_ir
nyhHXVRH
public FileAccessI(String sName,long nPos) throws IOException J~@W":v
{ FDGzh/
oSavedFile = new RandomAccessFile(sName,"rw"); u[wDOw
this.nPos = nPos; xw~oR|`U
oSavedFile.seek(nPos); -yIx:*KI
} Frx_aGLH1
<Z1m9O "sy
5P);t9O6
public synchronized int write(byte[] b,int nStart,int nLen) b\NY!)B
{ ^'sy hI\
int n = -1; JGhK8E
try{ FhEfW7]0,
oSavedFile.write(b,nStart,nLen); U; #v-'Z
n = nLen; [w FK!?
} JsX}PVuL
catch(IOException e) n;.);
{ HXB& 6
e.printStackTrace (); k1D|Cpnp
} zP!j {y4w
PMj!T \B|
(3m^@2i
return n; D|C!KF (
} 2-#&ktM%V
Jjx1`S*i
{|q(4(f"Iu
} [GW;RjPE
x)kp*^/
sdQ"[`~2R
/* -0*z"a9<p8
**SiteInfoBean.java ^7`gf
*/ -zm-|6[Wi
package NetFox; NF*Z<$'%
<q4<3A
?*f2P T?`
public class SiteInfoBean { pc](
$)jf
Kl :x?"g)
private String sSiteURL; //Site's URL 7}fT7tsN
private String sFilePath; //Saved File's Path g % 8@pjk
private String sFileName; //Saved File's Name K@!Gs'Op
private int nSplitter; //Count of Splited Downloading File @B>pPCowa
lM%3 ?~?Q&
t\,XG
public SiteInfoBean() x?G"58
{//nSplitter的缺省值为5 f2M}N
//default value of nSplitter is 5 Zx%6pZ(.
this("","","",5); )#025>$z
} ,D{D QJ(B
z7O$o/E-*
-pm%F8{T]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G@6F<L~$1
{ +nQp_a1{9%
sSiteURL= sURL; ^[hx`Rh`t
sFilePath = sPath; jtQ}
sFileName = sName; $xq$
this.nSplitter = nSpiltter; +(8Z8]Jf
t``q_!s}F
}Gh95HwE
} 5P![fX|5
1c*XmMB
cFloaCz
public String getSSiteURL() )s>R~7
{ u:%Ln_S
return sSiteURL; `:YCOF
} DDp\*6y3l
zIbrw9G
vW`[CEm^X
public void setSSiteURL(String value) $3^Cp_p6
{ ~qezr\$2
sSiteURL = value; P?j;&@$^e
} Ew*SA
&[y+WrGG
-5#cfi4^*
public String getSFilePath() UKp^TW1^
{ }5lC8{wZ
return sFilePath; I@:"Qee
} b VcA#7 uA
O#x=iZI
;><m[l6
public void setSFilePath(String value) P$*9Z@
{ M^jEp
sFilePath = value; cng166}1A
} K aNO&%qX
+PKd </*]
KLgg([
public String getSFileName() p'\zL:3
{ \"6?*L|]
return sFileName; p;.M.
} 1;eWnb(
2$FH+wuW
`j!XWh*$
public void setSFileName(String value) w[OUGn'
{ e@7UL|12
sFileName = value; Tb}op XYK
} QAX3*%h
1C(sBU"
x.Tulo0/
public int getNSplitter() 4|;Ys-Q
{ 61](a;Di
return nSplitter; oqbhb1D1<
} H`1q8}m
H h35cj
_fS4a134R
public void setNSplitter(int nCount) |!{Y:f;
{ *auT_*
nSplitter = nCount; wU|jw(
} ch33+~Nn
} z `jLKPP!=
U7HfDDh
OAf}\
/* %F\.1\&eE
**Utility.java _{$<s[S
*/ T"1=/r$Ft
package NetFox; pfHfw,[
AkCy C1
}46Zfg\T6n
public class Utility { nDyA][
3^5h:OaT
E;wT4 T=
public Utility() i|m8#*Hd
{ HuR774f[
FC WF$'cO
F)4I70vG
} 2MmHO2
'2 Y8
//线程睡眠 .5);W;`X
public static void sleep(int nSecond) ~'F.tB
{ S|af?IW
try{ T}/|nOu 5
Thread.sleep(nSecond); [5ncBY*A7
} f@[)*([
catch(Exception e) Y`d@4*FN$
{ '#SZ|Rr6tX
e.printStackTrace (); ,:2Z6~z{
} |?nYs>K
} $@O?
eK5~YM:o
//日志 ug.|ag'R
public static void log(String sMsg) ^VW]Qr!
{ Bh'!aipk
System.err.println(sMsg); &xA>(|a\&-
} vxOnv8(
(E7"GJ
J%n#uUs
public static void log(int sMsg) l fFRqZ
{ @,7r<6E
System.err.println(sMsg); Pm%5c\ef
} P(DEf(
} -%| ] d ;
;Yv{)@'Bc
x)Zb:"
/* :,M+njcFc
**TestMethod.java 'HJ+)[0X*
*/ v 2p
package NetFox; p(nO~I2E
IaQm)"Z
({@"{
public class TestMethod { 5D2mZ/
q*5L",
7VG*Wu
public TestMethod() -agB ]j
{ ///xx/weblogic60b2_win.exe [VqiF~o,
try{ Wp+lI1t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \4^zY'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b8Z_oN5!
SiteFileFetch fileFetch = new SiteFileFetch(bean); S(nQ?;9,
fileFetch.start(); .dVV# H
} g],]l'7H
catch(Exception e){e.printStackTrace ();} $STGH
cJbv,RV<
v#d(Kj
} ~JNE]mg
MgJ5FRQ
Ook\CK*nKe
public static void main(String[] args) CM$&XJzva
{ ]f?r@U'AS|
new TestMethod(); 7)[2Ud8
} uF1 4;
} UJQTArf
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